Question

The system of equations can be solved using linear combination to eliminate one of the variables. 2x − y = −4 → 10x − 5y = −20 3x + 5y = 59 → 3x + 5y = 59 13x = 39 Which equation can replace 3x + 5y = 59 in the original system and still produce the same solution?

Answer 1

Answer:

$13x=39$

Step-by-step explanation:

Given

$2x - y = -4 \to 10x - 5y =-20$

$3x +5y =59 \to 3x +5y = 59$

Required

What can replace $3x +5y = 59$ ?

We have:

$10x - 5y =-20$

and

$3x +5y = 59$

Add up both equations:

$10x +3x-5y+5y=-20+59$

$10x +3x=39$

$13x=39$

Since $13x=39$ is a result of $10x - 5y =-20$ and $3x +5y = 59$,

$13x=39$ can replace $10x +3x=39$