How do you solve 6x - 2y = -166x−2y=−16 and 4x + 4y = -32 4x+4y=−32?

2 Answers
Deepak G.
Aug 10, 2016

x=-4x=−4
y=-4y=−4-

Explanation:

6x-2y=-166x−2y=−16 and
4x+4y=-324x+4y=−32
or
2x+2y=-162x+2y=−16
or
x+y=-8x+y=−8
Adding up the equations 6x-2y=-166x−2y=−16 and 2x+2y=-162x+2y=−16
We get
6x-2y+2x+2y=-16-166x−2y+2x+2y=−16−16
or
8x=-328x=−32
or
x=-32/8x=−328
or
x=-4x=−4--------------------Ans 11
By putting the value x=-4x=−4 in the equation x+y=-8x+y=−8
We get
-4+y=-8−4+y=−8
or
y=4-8y=4−8
or
y=-4y=−4-----------------------Ans 22

EZ as pi
Aug 10, 2016

x = -4 and y = -4x=−4andy=−4

Explanation:

Neither of the equations is in the simplest form. Let's do that first and see what we end up with.

6x-2y = -16 " "(div 2)" " rArr 3x-y =-8 ..........A

4x + 4y = -32 " " (div 4) " " rArr x+y =-8 ............B

We notice that +y and -y are additive inverses which will add to 0 if we add equations A and B together.

color(white)(................)3x-y =-8 ..........A
color(white)(.................)x+y =-8 ............B

A+B color(white)(.........) 4x = -16
color(white)(.....................)x = -4
color(white)(....................)y = -4

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