SOLUTION: Solve the system by any method. 0.7x+0.8y=-5.3 0.6x-0.9y=1.8

Algebra ->  Rational-functions -> SOLUTION: Solve the system by any method. 0.7x+0.8y=-5.3 0.6x-0.9y=1.8      Log On


   

Question 158549: Solve the system by any method.
0.7x+0.8y=-5.3
0.6x-0.9y=1.8
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the system by any method.
system%280.7x%2B0.8y=-5.3%2C+0.6x-0.9y=1.8%29

First get rid of the decimals by multiplying every
term on both sides of both equations by 10.

system%287x%2B8y=-53%2C+6x-9y=18%29

To make the y's cancel, multiply the
top equation by 9 and the bottom equation
by 8

system%2863x%2B72y=-447%2C+48x-72y=144%29

Now add vertically term by term:

system%2863x%2B72y=-447%2C+48x-72y=144%29

111x+=+-333

Divide both side by 111

x+=+-3

Sustitute that into

6x-9y=18

6%28-3%29-9y=18

-18-9y=18

Add 18 to both sides:

-9y=36

Divide both sides by -9:

y=-4

Edwin