Question 805693: The question for solving systems using substitution is: 6x-4y=54 and -9x+2y=-69
I tried to solve it by getting x variable alone in 6x-4y=54 and rewrote it into 6x=-4y+54/6
I don't know if I am doing it right,thanks.
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! The question for solving systems using substitution is: 6x-4y=54 and -9x+2y=-69
I tried to solve it by getting x variable alone in 6x-4y=54 and rewrote it into
-----------
6x=-4y+54/6 **** You divided 54 by 6, but not the other terms.
============
6x-4y=54
-9x+2y=-69
=============
Usually, you solve one eqn for x or y, then sub into the other one. For this one, that would cause fractions, so I'll solve for 2y and sub for that.
3x-2y = 27 --> 2y = 3x - 27
-9x+2y=-69
------
Sub for 2y in the 2nd eqn
-9x+2y=-69
-9x+ (3x-27) = -69
-6x = -42
x = 7
------------
Sub for x in any eqn and find y
|
|
|
