Question

I Just Know I Did This System of Equation Wrong...

Answer 1

{4x - 5y = 2
{3x - y = 8

Answer 2

I decided to so the substitution method. So I changed the second equation to slope-intercept so I can substitute.

y = 3x - 8

4x - 5(3x - 8) = 2
4x - 15x - 40 = 2
+40 +40
-11x = 42
---- ---
-11 -11
x = -3.81818181818

\[3\times3.81818181818-y=8\]\[-11.45454545454-y=8\]\[+-11.45454545454~~~~+11.45454545454\]--------------------------------------\[y=-19.454545454\](-3.81818181818, −19.454545454)

I just know that this isn't correct...

Answer 3

@Potatoes.ramu @mathman806 @mathmale @courter98 @ganeshie8 @thomaster

Answer 4

First off, try to always leave answers in exact form, unless otherwise instructed.

Answer 5

I would try Mathway. Thats a good place to solve these!

Answer 6

@Sky.Dance they can't solve systems of equations. ;-; and @austinL what do you mean?

Answer 7

And in your third line, a negative multiplied by a negative is what?

Answer 8

And exact form means that you need to leave it in fraction form, or in radical form if need be. Decimals are only approximations of the final answer.

Answer 9

Try multiplying the second equation throughout by 5 and then add the two equations!

Answer 10

@Darry&Gator

Answer 11

Okay, hold on a second. @Potatoes.ramu

Answer 12

Figured it out now?

Answer 13

Yes...\[3x-y=8\]\[\times5~~\times5~\times 5\]-------------\[15x-5y=40\]\[+~4x-5y=2\]--------------\[19x-10y=42\]

Answer 14

Omg! Wait sorry! Subtract the two. Don't add.. SORRY!

Answer 15

Okay, let me subtract it.

Answer 16

Okay, thank you. :D Now I can put that x-value into the other equation.

Answer 17

Exactly! :) And no problem! :)

Answer 18

\[y=-\frac{ 16 }{ 95 }\]

Answer 19

Got it?

Answer 20

I mean, do you have the answers?

Answer 21

I think.\[(\frac{ 11 }{ 38 }. \frac{ 16 }{ 95 })\]

Answer 22

Oh, the y-value is negative.

Answer 23

Good! :)