SOLUTION: the product of two integers is 80. one number is 8 more than 3 times the other number. find the number.

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: the product of two integers is 80. one number is 8 more than 3 times the other number. find the number.      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 670541: the product of two integers is 80. one number is 8 more than 3 times the other number. find the number.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let the integers be x & y
xy=80
OR
x=80/y
x=3y+8
3y+8= 80/y
multiply equation by y
3y^2+8y=80
3y^2+8y-80=0
a= 3 b= 8 c= -80

b^2-4ac= 64 - -960
b^2-4ac= 1024
sqrt%28%091024%09%29= 32
y=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
y1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29 )/
y1=( -8 + 32 )/ 6
y1= 4
y2=( -8 - 32 )/ 6
y2= -6.67
Ignore negative value it is not an integer
y = 4
The integers are 4 & 20