SOLUTION: One number is 4 less than three times a number. If the product of these two numbers is 84, find the numbers.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: One number is 4 less than three times a number. If the product of these two numbers is 84, find the numbers.      Log On


   

Question 708712:
One number is 4 less than three times a number. If the product of these two numbers is 84, find the numbers.
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
X=3Y-4
XY=84
(3Y-4)Y=84
3Y^2-4Y-84=0
(3Y-14)(Y-6)=0
Y-6=0
Y=6 ANS.
X=3*6-4
X=18-4=14 ANS.
PROOF:
6*14=84
84=84