Question 158549
Solve the system by any method.
{{{system(0.7x+0.8y=-5.3, 0.6x-0.9y=1.8)}}}
<pre><font size = 4 color = "indigo"><b>
First get rid of the decimals by multiplying every
term on both sides of both equations by 10.

{{{system(7x+8y=-53, 6x-9y=18)}}}

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

{{{system(63x+72y=-447, 48x-72y=144)}}}

Now add vertically term by term:

{{{system(63x+72y=-447, 48x-72y=144)}}}

{{{111x = -333}}}

Divide both side by 111

{{{x = -3}}}

Sustitute that into

{{{6x-9y=18}}}

{{{6(-3)-9y=18}}}

{{{-18-9y=18}}}

Add 18 to both sides:

{{{-9y=36}}}

Divide both sides by -9:

{{{y=-4}}}

Edwin</pre>