SOLUTION: Four times a first number decreased by a second number is 25 . The first number increased by three times the second number is 16 . Find the numbers

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Question 1032705:
Four times

a first number decreased by a second number is 25
.
The first number increased by three times

the second number is 16
.
Find the numbers
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
let a = the first number
let b = the 2nd number
:
Write an equation for each statement
:
Four times a first number decreased by a second number is 25.
4a - b = 25
The first number increased by three times the second number is 16
a + 3b = 16
a = -3b + 16; use this for substitution in the 1st equation
:
4(-3b+16) - b = 25
-12b + 64 - b = 25
-12b - b = 25 - 64
-13b = -39
b = -39/-13
b = +3
Find a
a = -3(3) + 16
a = -9 + 16
a = 7
:
Find the numbers 7 & 3
:
:
Check this in the 1st statement
"Four times a first number decreased by a second number is 25"
4(7) - 3 = 25