56.6k views
5 votes
Solve the following system of equations.

−1.6x + 0.2y = 8.8

0.5x + 1.2y = −7.8

x = ?
y = ?

1 Answer

2 votes
So!

This is a system of equations. So there are two ways to solve the problem: elimination or substitution.

Now...I'll use the elimination method, where you add the equations in such a way that one of the variables cancel.

I choose to eliminate"y". the coefficients are 0.2 and 1.2....uh oh....they don't cancel....what do I do?

multiply both numbers by the l.c.m. (lowest common multiple), and that's 1.2.

multiply the whole first equation by 6 to get "-9.6x+1.2y=52.8 "
and multiply the whole second equation by 1 to get "0.5x+1.2y=-7.8"

So "y" has the same coefficient, but we need them to cancel, remember?

Make one of the equations negative.
Using the second one, multiply by d - 1: -0.5x-1.2y = 60.6

Now we can add the equations!

Add the "x's" and the "y's" and constants together.

The result is the following: -10.1x = 16.6
x = -6

Now take the value of "x" and put it into one of the equations.

Let's use the first one: -1.6x+0.2y=8.8
-1.6(-6) + 0.2y = 8.8
9.6 + 0.2y = 8.8
0.2y = -0.8
y = -4

Therefore, the answers are "x = -6" and "y = -4".

Hope this helps.






















User RippeR
by
8.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories