Verified answer

{у₃ + у₇ = 180

{5y₇ = y₃

{у₃ = 180 − y₇

{5y₇ = y₃

→ {5y₇ = 180 − y₇

5y₇ + y₇ = 180

6y₇ = 180

y₇ = 180÷6

y₇ = 30°

→ y₃ = 5 × 30° = 150°

Ответ: y₃ = 150°; y₇ = 30°.