If A and B both lie on the straight line, all we need to do is to calculate the gradient using (2, -5) and (5, 2) to see if the result agrees with the equation.

m = (-5-2)/(2-5) = 7/3

The calculated gradient with the 2 points A and B is 7/3. But, the equation states that the gradient is 3, so the 2 points are not on the line.

To find out is A and B is on the line, we can just substitute in the coordinates into the equation.

For Point A, the coordinates are (2,-5) So the equation is y=3x-5, therefore the equation will become: -5=3(2)-5 -5=6-5 -5≠1 We can easily conclude that A does not lie on the graph.

For B, we can also use the same method. B's coordinates are (5, -2) So the equation will become -2=3(5)-5 -2=15-5 -2≠10

Again, we also can easily conclude that B is also not on the line.

How would you determine if the points A (2, -5) and B (5, 2) lie on the straight line y = 3x - 5?

We can substitute the coordinates into the equation. In A, we can the substituted equation is -5=3(2)-5. The equation obviously does not match. Both sides of the equation are unequal. Thus, A is not the point on the line.

Next, for B, the equation will be 2=3(5)-5 which is 2=10. The equation is invalid once again, and we can conclude that B is not a point on the graph.

In order to solve this, we just need to substitute the points into the equation… If the points satisfy the equation, the the points do sit on the straight line, y=3x-5.

So here is my attempt to solve this question:

For ordered pair (2,-5),

y=3(2)-5 =6-5 =-1, Therefore, since (y) is (-1) and not (-5), this ordered pair does not satisfy the equation y=3x-5 and hence, this coordinate does not lie on the equation of the straight line.

For ordered pair (5,2),

y=3(5)-5 =15-5 =10, Therefore since (y) is (10) and not (2), this ordered pair does not satisfy the equation y=3x-5 and hence, this coordinate does not lie on the equation of the straight line.

We can substitute y=mx+c with y=3x-5 If both points A and B lie on the same line, we can just find the gradient of a and b: m= (-5-2)/(2-5)= 2 1/3

The calculated gradient with the 2 points A and B is 2 1/3. But the gradient stated in the question is 3 thus, point A and B are not on the straight line.

In order for both points A and B to line on a straight line, their gradient* has to be the same as the given line. Hence, we calculate the gradient: (2 (-5)) / (5 - 2) = 7/3

As you can see, the gradient of the given line and *[the gradient of the line made when points A and B are joined] are not the same. Thus points A and B do not lie on the line.

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ReplyDeleteA is obviously not on the line. -5 is the y intercept, thus if A is on the line, the coordinates would be (0, -5)

ReplyDeleteTo find out if B is on the line, substitute -5 as c. Then substitute x and y with the coordinates in B. If x and y is on the line, c=5 would be found.

Grp 3

We can substitute the y and x in y=3x-5 with the x and y points in A and B. So these are the workings:

ReplyDeleteA:

y=3x-5

-5=(3x2)-5

-5=6-5

-5=1

Since -5 does not equal to 1, then point A is definitely not on the straight line.

B:

y=3x-5

2=(5x3)-5

2=15-5

2=10

Since 2 does not equal to 10, then B is not on the line.

Group 1

If A and B both lie on the straight line, all we need to do is to calculate the gradient using (2, -5) and (5, 2) to see if the result agrees with the equation.

ReplyDeletem = (-5-2)/(2-5)

= 7/3

The calculated gradient with the 2 points A and B is 7/3. But, the equation states that the gradient is 3, so the 2 points are not on the line.

To find out is A and B is on the line, we can just substitute in the coordinates into the equation.

ReplyDeleteFor Point A, the coordinates are (2,-5)

So the equation is y=3x-5,

therefore the equation will become:

-5=3(2)-5

-5=6-5

-5≠1

We can easily conclude that A does not lie on the graph.

For B, we can also use the same method. B's coordinates are (5, -2)

So the equation will become

-2=3(5)-5

-2=15-5

-2≠10

Again, we also can easily conclude that B is also not on the line.

Group 4

How would you determine if the points A (2, -5) and B (5, 2) lie on the straight line y = 3x - 5?

ReplyDeleteWe can substitute the coordinates into the equation. In A, we can the substituted equation is -5=3(2)-5. The equation obviously does not match. Both sides of the equation are unequal. Thus, A is not the point on the line.

Next, for B, the equation will be 2=3(5)-5 which is 2=10. The equation is invalid once again, and we can conclude that B is not a point on the graph.

Group 2

we can subsitute the actual numbers to the equations

ReplyDeleteit would look like "-5 = 6 - 5" and this is obviously wrong, hence A does not lie on the line

for B it will look like "2 = 15 - 5" which is once again wrong since it does not add up, hence B does not lie on the line

group 1

In order to solve this, we just need to substitute the points into the equation… If the points satisfy the equation, the the points do sit on the straight line, y=3x-5.

ReplyDeleteSo here is my attempt to solve this question:

For ordered pair (2,-5),

y=3(2)-5

=6-5

=-1,

Therefore, since (y) is (-1) and not (-5), this ordered pair does not satisfy the equation y=3x-5 and hence, this coordinate does not lie on the equation of the straight line.

For ordered pair (5,2),

y=3(5)-5

=15-5

=10,

Therefore since (y) is (10) and not (2), this ordered pair does not satisfy the equation y=3x-5 and hence, this coordinate does not lie on the equation of the straight line.

Oh… and also I am from Group 2.

DeleteWe can substitute y=mx+c with y=3x-5 If both points A and B lie on the same line, we can just find the gradient of a and b: m= (-5-2)/(2-5)= 2 1/3

ReplyDeleteThe calculated gradient with the 2 points A and B is 2 1/3. But the gradient stated in the question is 3 thus, point A and B are not on the straight line.

Group 2(forgot to mention it)

DeleteHow would you determine if the points A (2, -5) and B (5, 2) lie on the straight line y = 3x - 5?

ReplyDeleteUsing y=mx +c ,

m = gradient

= y1-y2

-------------

x1-x2

= -5 - 2

------------

2 - 5

= -7

-------------

-3

= 2.33 (3 sf)

y= mx+c

y = 2.33 x + -5

Thus , points A and B are not on the same line.

Group 4

A) y=mx+c

ReplyDeleteIf (x,y) = (2,-5)

-5=3(2)-5

=1

Since the answer is not 0 the coordinates do not lie on the line.

B) if (x,y) = (5,2)

then 2=3(5)-5

=10

so it is also not on the line as any point that lies on the line must have a final answer of 0 after being simplified.

Group:4

ReplyDeletePOINT A =(2,-5)

So y=3x-5,

thus -5=3(2)-5

-5=6-5

-5≠1

SO obviously Point A is not on the Line

Point B(5, -2)

So -2=3(5)-5

-2=15-5

-2≠10

SO Point B is also not on the line

Grp 3 :D

Point A=(2,-5)

ReplyDeleteSubstitute x & y coordinates with x & y in y=3x-5

Thus, y=3x-5

=-5=6-5

-5=1 which is wrong, so A is not on the line

Point B can also be done with this method

y=3x-5

2=15-5

2=10 which is again wrong

Both points A and B are not on the line y=3x-5

Group 1

This comment has been removed by the author.

ReplyDeleteIn order for both points A and B to line on a straight line, their gradient* has to be the same as the given line. Hence, we calculate the gradient:

ReplyDelete(2 (-5)) / (5 - 2) = 7/3

As you can see, the gradient of the given line and *[the gradient of the line made when points A and B are joined] are not the same. Thus points A and B do not lie on the line.

Group 3