Question

x:y+z:y=10, unde x+z=40. y=?

Answer 1

$x \div y + z \div y = 10$

$\frac{1}{y} (x + z) = 10$

$\frac{1}{y} \times 40 = 10$

$\frac{40}{y} = 10$

$y = \frac{40}{10}$

$y = 4$

Answer 2

x / y + z/ y = 10 ⇒ ( x + z) / y = 10 ⇒ x + z = 10 y 

x + z = 40 

x + z = 10 y = 40 ⇒ y = 40 : 10 ⇒ y = 4