Question

solve.
$x + 2y = 7$
$10x + 10y = -10$
(□, □)

Explanation:

Step1: Simplify the second equation

Divide the second equation \(10x + 10y=- 10\) by 10, we get \(x + y=-1\), then express \(x\) as \(x=-1 - y\).

Step2: Substitute \(x\) into the first equation

Substitute \(x = - 1-y\) into \(x + 2y=7\), we have \((-1 - y)+2y = 7\).
Simplify the left - hand side: \(-1 - y+2y=-1 + y\). So the equation becomes \(-1 + y=7\).
Add 1 to both sides: \(y=7 + 1=8\).

Step3: Find the value of \(x\)

Substitute \(y = 8\) into \(x=-1 - y\), then \(x=-1-8=-9\).

Answer:

\((-9,8)\)