Question

What is the solution to the system of equations?
5x-3y=-9
2x-5y=4

Answer 1

@One098

Answer 2

Sorry if it takes me awhile to answer my internet is bad.

Answer 3

ok

Answer 4

First Step:
We have to make one of the variables cancel out when we add the two equations together.

Answer 5

We do this by multiplying the top equation by 5, and the the bottom equation by (-3). Then when we add the two together the y's will cancel out. The equations are now:
\[25x-15y=45\]
and
\[-6x+15y=-12\]
Then when we add the two together we have:
\[19x=33\]
Understand so far?

Answer 6

yea

Answer 7

Step Two:
Solve for x.

Answer 8

divide 19 on both sides right

Answer 9

\[x = \frac{ 33 }{ 19 }\]

Answer 10

right!

Answer 11

So x = 1.74

Answer 12

plug in x

Answer 13

Step Three:
Take that 'x' value we just found, and put it back into one of the two original equations, and solve for 'y'.

Answer 14

ok

Answer 15

That looks like this:
\[2(1.74)-5y= 4\]
\[3.48 - 5y = 4\]
\[-5y = 0.52\]
\[y = -0.104\]

Answer 16

yea

Answer 17

So these two equations cross at (1.74,-0.104)

Answer 18

are you sure

Answer 19

its not letting me put it all in

Answer 20

Yup, we can check by graphing the two individual equations.
Go here: https://www.desmos.com/calculator and type in 5*x-3*y = 9 for the first equation and 2*x - 5*y = 4.

Answer 21

its -3 -2

Answer 22

thank you

Answer 23

I didn't notice the (-) in the first equation sorry! :S