SOLUTION: Twice one number minus a second number is five. Twice the second number plus the first number is eight. Find the numbers.

Question 207947This question is from textbook
: Twice one number minus a second number is five. Twice the second number plus the first number is eight. Find the numbers. This question is from textbook

Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
let your first number = x
let your second number = y
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Twice the first number minus a second number is five.
equation for this is:
2x - y = 5
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Twice the second number plus the first number is eight.
equation for this is:
2y + x = 8
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from the first equation you can solve for y to get y = 2x-5
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you can substitute for y in the second equation to get:
2 * (2x - 5) + x = 8
this becomes:
4x - 10 + x = 8
which becomes:
5x - 10 = 8
which becomes:
5x = 18
which becomes:
x = 3.6
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you can substitute for x in the first equation to get:
2 * 3.6 - y = 5
this becomes:
7.2 - y = 5
add y to both sides of this equation and subtract 5 from both sides of this equation to get:
y = 7.2 - 5
which becomes:
y = 2.2
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you have x = 3.6
and y = 2.2
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substitute in first equation to get:
2 * 3.6 - 2.2 = 5 which becomes 7.2 - 2.2 = 5 which becomes 5 = 5
substitute in second equation to get:
2 * 2.2 + 3.6 = 8 which becomes 4.5 + 3.6 = 8 which becomes 8 = 8
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answers prove out correct and are:
x = 3.6
y = 2.2
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