Respuesta :

Answer:

x = 1

Explanation:

- 5x + 2y = 9

  • y = 7x
  • Insert 7x For 'y'

- 5x + 2(7x) = 9

  • Remove Parenthesis

-5x + 2 · 7x = 9

  • Multiply: 2 · 7 = 14

-5x + 14x = 9

  • Add: -5x + 14x = 9x

9x = 9

  • Divide Both Sides By 9

9x ÷ 9 = 9 ÷ 9

x = 1