Question

: x:y = 4:5 and 2y - x = 12

Answer 1

Step-by-step explanation:

In the equation 2, make x subject of the formula

$2y - x = 12$

$- x = 12 - 2y$

Divide both sides by -

$x = - 12 + 2y$

Substitute the value of x into equation 1

$\frac{x}{y} = \frac{4}{5}$

$\frac{ - 12 + 2y}{y} = \frac{4 }{5}$

Cross multiply

$5( - 12 + 2y) = 4 \times y$

$- 60 + 10y = 4y$

$10y - 4y = 60$

$6y = 60$

$y = 60 \div 6$

$y = 10$

substitute y=10 in equation 2

$2y - x = 12$

$2(10) - x = 12$

$20 - x = 12$

$- x = 12 - 20$

$- x = - 8$

$x = 8$

So therefore

x=8 and y=10