First you distribute what’s outside the parentheses (the -4)
-4•4= -4y
-4•-2= 8
New equation: -4y+8=12
Now you solve like a normal equation
12-8 is 4
New equation: -4y=4
Now divide
Answer:-1
1 i think 1 is the answer
I had this and it was b for me

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