The first one is correct, just match the numbers with the corresponding sides of each triangle
The first step to solving this is to multiply both sides of the equation by 3
8 + 10y = 9y - 12
now move the variable to the left side and change its sign
8 + 10y - 9y = -12
move the constant to the right side and change its sign
10y - 9y = -12 - 8
collect the like terms for y
y = -12 - 8 (it equals 1 when you subtract 10 from 9 which is the same is simply saying "y")
calculate the difference on the other side of the equals sign
y = -20
this means that the correct answer to your question is -20.
let me know if you have any further questions
:)
Are you trying to solve for c? if so c=8
I think it’s 9+2 because it say sum
