Answer:
x= 8, z= 118
Step-by-step explanation:
To find x, solve the equation with the one unknown x given by supplementary angles definition.
Supplementary angles sum up to 180° there for
8x +54 + 7x +6 = 180, group like terms
8x + 7x = 180 -54-6, combine like terms
15x = 120, divide both sides by 15
x = 8
To find z, solve for z the equation given by vertical angles definition.
Vertical angles are congruent there for
8x +54 = z, substitute x for 8
8·8 +54 = z, multiply then add
z = 118
