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
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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