Get the slope:
( 10-(-2) )/( 3 - (-1) ) = 3
Let's use letters to represent the ?'s.
y + k = m(x + 1)
Examine the equation:
Notice that if x were to equal -1, the equation would be equal to 0.
m(-1 + 1) = m(0) = 0
If x were to be -1, then y would have to be -2 since that is one of the points provided in the problem.
So now we have:
-2 + k = 0
Solve for k:
k = 2
So I know that 2 is the only number that will work for k.
Our new equation is y + 2 = m(x + 1)
Recall point slope form:
y - y1 = m(x - x1)
Our equation is in the same form as point slope form, so we know that m in our equation represents the slope.
We found the slope at the beginning, it was 3. So plug it in:
y + 2 = 3(x + 1)
Let's test our answer by plugging in a point. Let's try (3, 10):
10 + 2 = 3(3 + 1)
12 = 12
So our answer is correct:
y + 2 = 3(x + 1) is the answer.