Answer:
x = 21
Step-by-step explanation:
[tex](5 y + 10) \degree = y \degree + 90 \degree \\ (vertical \: \angle s) \\ \\ (5 y + 10 - y) \degree = 90 \degree \\ \\ (4 y + 10 ) \degree = 90 \degree \\ \\ 4y + 10 = 90 \\ \\ 4y = 90 - 10 \\ \\ 4y = 80 \\ \\ y = \frac{80}{4} \\ \\ y = 20 \\ \\ (5 y + 10) \degree = (5 \times 20 + 10) \degree = 110 \degree \\ \\ (5 y + 10) \degree + (3x + 7) \degree = 180 \degree \\ (linear \: pair \: \angle s) \\ \\ 110 \degree + (3x + 7) \degree = 180 \degree \\ \\ (3x + 7) \degree = 180 \degree - 110 \degree\\ \\ (3x + 7) \degree = 70 \degree \\ \\ 3x + 7 = 70 \\ \\ 3x = 70 - 7 \\ \\ 3x = 63 \\ \\ x = \frac{63}{3} \\ \\ x = 21[/tex]
