Im pretty sure it’s going to be a, because when you divide by the -6 you’re supposed to switch the sign
Please find attached photograph for your answer.
angles in a triangle add up to 180
so x = 180 - ( 70 + 90 ) = 20
this is because the two other angles in the both of the identical triangles are 70 and 90
5x(5w-z) -y(5w-z)
(5x-y)(5w-z)