Question

A line goes through the point (6,–2) and has a slope of –3. What is the value of a if the point (a,7) lies on the line? A =

Answer 1

Answer: The answer is 3.

Answer 2

Answer:

Step-by-step explanation:

Y = mx + b

slope(m) = 3/4

(3,7)...x = 3 and y = 7

now we sub...we r looking for b, the y int

7 = 3/4(3) + b

7 = 9/4 + b

7 - 9/4 = b

28/4 - 9/4 = b

19/4 = b

equation is : y = 3/4x + 19/4...lets put this in standard form

y = 3/4x + 19/4

-3/4x + y = 19/4...multiply by -4

3x - 4y = -19 <== standard form

if (x,5) is on the line

3x - 4y = -19.....sub in 5 for y

3x - 4(5) = -19

3x - 20 = -19

3x = -19 + 20

3x = 1

x = 1/3 <====so point a = (1/3,5)