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Inessa [10]
3 years ago
13

A first number plus twice a second number is 14. twice the first number plus the second totals 31. find the numbers.

Mathematics
1 answer:
topjm [15]3 years ago
4 0
------------------------------------------------------------
Define the two numbers
-----------------------------------------------------------
Let the first number be x.
Let the second number be y.

------------------------------------------------------------
Form equations and solve x and y
------------------------------------------------------------
x + 2y = 14 ------------------ (1)
2x + y = 31 ------------------ (2)

------------------------------------------------------------
Equation (1) x 2
------------------------------------------------------------
2x + 4y = 28  ---------------(1a)

------------------------------------------------------------
Equation (1a) - 2
------------------------------------------------------------
3y = 28 - 31
3y = -3
y = -1

------------------------------------------------------------
Substitute y = -1 into (1)
------------------------------------------------------------
x + 2(-1) = 14
x -2 = 14
x = 14 + 2
x = 16

------------------------------------------------------------
Answer: x =16, y = -1
------------------------------------------------------------

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a woman has $28,000. part is invested for one year in a certificate of deposit paying 7% interest, and the remaining amount in c
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First of all, we multiply the second equation with 100 in order to get rid of decimal values.

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