Question

Exercicio 2, preciso saber o valor de x

Answer 1

$5x + 4x = 180$ ⇒ $9x = 180$ ⇒ $x=20$

Answer 2

5x+4x=180
9x=180
x=180/9
x=20

5x=5.20=100 
4x=4.20=80