Question

Find the value of r in (4, r), (r, 2) so that the slope of the line containing them is −53

Answer 1

Answer:

C) 7

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Work Shown:

Use the slope formula

m = (y2-y1)/(x2-x1)

Plug in the given slope we want m = -5/3 and also the coordinates of the points. Then isolate r

m = (y2-y1)/(x2-x1)

-5/3 = (2-r)/(r-4)

-5(r-4) = 3(2-r) .... cross multiplying

-5r+20 = 6-3r

-5r+20+5r = 6-3r+5r .... adding 5 to both sides

20 = 6+2r

20-6 = 6+2r-6 ....subtracting 6 from both sides

14 = 2r

2r = 14

2r/2 = 14/2 .... dividing both sides by 2

r = 7

The slope of the line through (4,7) and (7,2) should be -5/3, let's check that

m = (y2-y1)/(x2-x1)

m = (2-7)/(7-4)

m = -5/3

The answer is confirmed

Answer 2

Answer:

C)  7

Correct answer

Step-by-step explanation: