Question

Find the equation in standard form which passes through (-2, -7) and (1, -1). You must show all work.

Answer 1

first we find the slope by using the slope formula :
slope (m) = (y2 - y1) / (x2 - x1)
(-2,-7)....x1 = -2 and y1 = -7
(1,-1)...x2 = 1 and y2 = -1
now we sub
slope(m) = (-1 - (-7) / (1 - (-2)
slope(m) = (-1 + 7) / (1 + 2)
slope(m) = 6/3 which reduces to 2

now we use y = mx + b.....and since we know the slope(m) = 2, we now need to find the y intercept(b)
slope(m) = 2
you can use either of your sets of points...(-2,-7)...x = -2 and y = -7
now we sub
y = mx + b
-7 = 2(-2) + b
-7 = -4 + b
-7 + 4 = b
-3 = b

so your equation is : y = 2x - 3
but we need it in standard form Ax + By = C

y = 2x - 3 --- subtract 2x from both sides
-2x + y = -3 --- multiply by -1 to make x positive
2x - y = 3 <== standard form

Answer 2

Ty So Much! That Really Helped Me. :)

Answer 3

good to hear...glad I could help :)