-4x + 7y = 18 4x - y = -3
solve using either the substitution or elimination method
pls show solving steps
will mark brainliest

Step-by-step explanation:

Subtract 7y7y from both sides.

-4x=18-7y−4x=18−7y

2 Divide both sides by -4−4.

x=-\frac{18-7y}{4}x=−

4

18−7y

x + 107

step-by-step explanation:

let's say that the number he had before the mistake was x. then, he will have 107 dollars more than this, so the answer is x + 107.

$20.01

step-by-step explanation:

the sale price is (1.00 - 0.77)($87), or 0.23($87), or $20.01.