Question

Need help with solving systems of equations. The equations are:

0.3x-0.2y=4
0.4x+0.5y=63/19

Answer 1

We can cancel out either x or y

Answer 2

yep, either or.

Answer 3

Let's cancel out y

To do so we multiply first equation by 5 and second equation by 2

Answer 4

need to cancel out those icky little decimals first it seems. I'm just getting horribly wrong answers by myslef

Answer 5

We get
1.5x-y=20
.8x+y=126/19

Answer 6

Getting rid of an icky decimal is as easy as multiplying every term by 10.

Answer 7

When we add two equation, y cancel; leaving us with
2.3x=506/19

Answer 8

yep mooby, it seems I had the steps in order but forgot to multiply my fraction as well. trying it out myself now to see if I get what you guys get

Answer 9

@Mooby true but why work with big numbers if you can work with little ones?

Answer 10

I like whole numbers. ;)

Answer 11

2.3 = 23/10 :-)

Answer 12

hmm getting x = 220/19

Answer 13

so thats the same as imranmeah91's 2.3x=506/19 yea?

Answer 14

Yes

Answer 15

yay! now I can prey I get the y right. Im absolutely horrible at the elimination method, and substitution wasn't looking any better.

Answer 16

if you divide both side by 2.3, you would get same answer

Answer 17

Im at -50/19 = y sound right?

Answer 18

0.3x-0.2y=4
0.4x+0.5y=63/19
y=4-0.3x
0.4x+0.5(4-0.3x)=63/19
0.4x+2-0.15x=63/19
0.4x+0.15x=(63/19)-2
0.55x=(63/19)-2
x=((63/19)-2)/0.55
y=4-0.3(((63/19)-2)/0.55)

Answer 19

yep its right :) got a correct on ym school webbie. Thanks for the help guys/gals!

Answer 20

I would multiply first equation by 10
3x-2y=40
3(220/19)-2y=40
y=-50/19