Question

x/20 igual y/15 e x + y igual a 7 qual e o valor de x e y

Answer 1

x/20 = y/15
20y = 15x 
4y = 3x

x + y = 7
x = 7 - y

4y = 3x
4y = 3 (7 - y)
4y = 21 - 3y
4y + 3y = 21
7y = 21
y = 21/7
y = 3

x = 7 - y
x = 7 - 3
x = 4

x = 4 e y = 3