Question

Urgent please help quick!!!

Solve the system of linear equations by substitution

5x+5y=-10
3x - 7y = 4​

Answer 1

Answer:

$x=-1\\y=-1$

Step-by-step explanation:

$5x+5y=-10\\3x-7y=4$

Let's solve the first equation for either x or y. I'll do it for x.

$5x+5y=-10$

Begin by subtracting 5y.

$5x=-5y-10$

Now divide by 5.

$x=\frac{-5y}{5}-\frac{10}{5}$

Simplify:

$x=-y-2$

Now substitute x in the second equation for this value.

$3x-7y=4\\3(-y-2)-7y=4$

Distribute;

$-3y-6-7y=4$

Add 6

$-3y-7y=4+6$

Combine like terms;

$-10y=10$

Divide by -10.

$y=\frac{10}{-10}\\ y=-1$

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Take this value of y and replace it in the first equation to find the value of x.

$5x+5y=-10\\5x+5(-1)=-10\\5x-5=-10\\5x=-10+5\\5x=-5\\x=\frac{-5}{5}\\ x=-1$