SOLUTION: The sum of three integers is 40. The first integer is four times the sum of the second and third. The second is twice the opposite of the third. What are the integers?

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Question 1077334: The sum of three integers is 40. The first integer is four times the sum of the second and third. The second is twice the opposite of the third. What are the integers?
Answer by MathLover1(20849) About Me  (Show Source):
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The sum of three integers is 40. The first integer is four times the sum of the second and third. The second is twice the opposite of the third. What are the integers?
let’s three integers be x, y, and z
if the sum of three integers is 40, we have
x%2By%2Bz=40........eq.1
if the first integer is four times the sum of the second and third, we have

x=4%28y%2Bz%29.......eq.2
if the second is twice the opposite of the third, we have
y=2%28-z%29
y=-2z.....eq.3...go to eq2 and substitute y
x=4%28-2z%2Bz%29
x=4%28-z%29
x=-4z.............eq.2a
go to x%2By%2Bz=40........eq.1, substitute x from eq.2a and y from eq.3

-4z-2z%2Bz=40........eq.1
-5z=40
z=40%2F-5
highlight%28z=-8%29
find y
y=-2%28-8%29
highlight%28y=+16%29
find x
x=-4%28-8%29.............eq.2a
highlight%28x=+32%29
so, your integers are:highlight%28+32%29, highlight%2816%29, and highlight%28-8%29
check their sum:
x%2By%2Bz=40........eq.1
32%2B16-8=40
48-8=40
40=40