SOLUTION: Twice the first number plus 3 times the second number is 87. Three times the first minus twice the second is -6. Find the numbers.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Twice the first number plus 3 times the second number is 87. Three times the first minus twice the second is -6. Find the numbers.      Log On


   



Question 1175725: Twice the first number plus 3 times the second number is 87. Three times the first minus
twice the second is -6. Find the numbers.

Found 2 solutions by Solver92311, Alan3354:
Answer by Solver92311(821) About Me  (Show Source):
You can put this solution on YOUR website!






Solve the 2X2 System for and by any convenient means (Substitution, Elimination, Cramer's Rule, etc.). I would recommend Cramer's Rule as it works out quite tidily (no really ugly arithmetic)

John

My calculator said it, I believe it, that settles it

From
I > Ø

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Twice the first number plus 3 times the second number is 87.
---
2a + 3b = 87 Eqn 1
================
Three times the first minus twice the second is -6. Find the numbers.
---
3a - 2b = -6 Eqn 2
================================
4a + 6b = 174 Eqn 1 times 2
9a - 6b = -18 Eqn 2 times 3
----------------------------------- Add
13a = 156
a = 12
etc