Answer:
x = 7
y = 1
Explanation:
1) x−2y = 5
2) −7x+4y = −45
Solving by substitution means we need to get rid of one of the variable.
We can do that as follows:
Multiply
the first equation by 2.
2x - 4y = 10
Add both equations up.
2x - 4y - 7x + 4y = 10 - 45
Add/subtract
like terms
.
-5x = -35
It can be written in
positive form
since both sides are negative.
5x = 35
Divide
both sides by 5.
x = 7
To find the value of y, replace x with 7 in the first equation:
7 - 2y = 5
Subtract
7 from both sides.
-2y = -2
Again, it can be written in positive form.
2y = 2
Divide both sides by 2.
y = 1