Question

Solve the Solve the simultaneous equations 2x+3y=20 x+5y=31

Answer 1

Answer:

$x = 1$   and   $y = 6$

Step-by-step explanation:

Given

$2x + 3y = 20$

$x + 5y = 31$

Required

Solve for x and y

Make x the subject in the second equation

$x = 31 - 5y$

Substitute 31 - 5y for x in $2x + 3y = 20$

$2(31 - 5y) + 3y = 20$

$62 - 10y + 3y = 20$

$62 - 7y = 20$

Collect like terms

$-7y = 20 - 62$

$-7y = - 42$

Solve for y

$y = \frac{-42}{-7}$

$y = 6$

Substitute 6 for y in $x = 31 - 5y$

$x = 31 - 5 * 6$

$x = 31 - 30$

$x = 1$