Question

8. Solve for y. **THINK! a) what type of angles do you have? b) what is their
relationship (add up to 90, add up to 180, or congruent)? c) set up an equation
and solve *

Answer 1

Answer:

a. Linear pair (supplementary)

b. Add up to 180°

c. $y = 20$

Step-by-step explanation:

78° and (5y + 2)° are a linear pair. They are supplementary, and add up to 180°.

Therefore, the following equation expresses their relationship:

$78 + (5y + 2) = 180$

Solve for y

$78 + 5y + 2 = 180$

$78 + 2 + 5y = 180$

$80 + 5y = 180$

Subtract 80 from both sides

$80 + 5y - 80 = 180 - 80$

$5y = 100$

Divide both sides by 5

$\frac{5y}{5} = \frac{100}{5}$

$y = 20$