Use substitution.
y = 2 - x and y = 4x + 7 can become
2 - x = 4x + 7
Now solve for x
-5 = 5x
-1 = x
Now plug -1 for x in either equation.
y = 2 - x -> y = 2 - (-1) -> y = 3
y = 4x + 7 -> y = 4*-1 + 7 -> y = -4 + 7 -> y = 3
So C) is the correct answer.

y - y₁ = m(x - x₁)
y - (-10) = -1⁴/₂₁(x - 6)
y + 10 = -1⁴/₂₁(x) + 1⁴/₂₁(6)
y + 10 = -1⁴/₂₁x + 7¹/₇
- 10 - 10
y = -1⁴/₂₁x - 3¹/₇
>
Positive integers are always greater.
Find factorial 6: 6! = 6*5*4*3*2*1 = 720