Write an equation that represents the line that passes through the points (-1,-2) and (3,10)

Answer 1

m = (-2 - 10)/(-1 - 3) = -12/-4 = 3

Now, two ways. You pick which you like. Either way can use either point.

y - 10 = 3(x - 3)

y - 10 = 3x - 9

y = 3x + 1

orrrrr...

-2 = 3(-1) + b

-2 = -3 + b

b = -1

y = 3x - 1

Answer 2

General line equation: y = ax + b

Line passes through point (-1,-2), we have:

-2 = (-1)a + b

-2 = -a + b

Or a - b = 2

Line passes through point (3,10), we have:

10 = 3a + b

Now we have 2 equations with 2 variables:

a - b = 2 --> a = b + 2

3a + b = 10 --> 3(b + 2) + b = 10 --> b = 1

a = b + 2 = 1 + 2 = 3

==> After plunging a and b into the general line equation y = ax + b, The equation line is

y = 3x + 1