Answer:
x = 1/5
y = 6
Explanation:
System:
{5x + y = 7
{20x + 2 = y
First equation:
5x + y = 7 -> y = -5x + 7
Plug into second equation:
20x + 2 = -5x + 7
Subtract 2 from both sides:
20x = -5x + 5
Add 5x to both sides:
25x = 5
Divde both sides by 25:
x = 5/25 -> 1/5
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Come back to the first equation:
5x + y = 7
Plus in our x:
5(1/5) + y = 7
Multiply:
1 + y = 7
Subtract 1 from both sides:
y = 6
Hope this helps, have a nice day! :D