Question

Rodrigo is looking at the system below.
2x + 3y = 9
x - 8y = 11
To solve, he first multiplied the second equation by two and then subtracted the equations.
Is Rodrigo correct? Justify your answer. If incorrect, describe the error.

Answer 1

@Dbzfan836

Answer 2

i hate these

Answer 3

use geogebra, a free graphing software. enter things like 2x+3y=9, and it will help alot

Answer 4

ive acyually tried that but it nearly destroyed my pc

Answer 5

idk how but it did

Answer 6

no, thats a fake one. heres the link:
( ͡° ͜ʖ ͡°)
www.geogebra.org/cms/en/download

Answer 7

one sec

Answer 8

how much are you typing @texaschic101 ??

Answer 9

you can multiply the 2nd equation by -2, and then add them...
2x + 3y = 9
x - 8y = 11---->(-2)
----------------
2x + 3y = 9
-2x + 16y = -22
---------------add
19y = - 13
y = -13/19

OR
you can multiply second equation by 2, then subtract them
2x + 3y = 9
x - 8y = 11---->(2)
----------------
2x + 3y = 9
2x - 16y = 22
--------------subtract

2x + 3y = 9
-2x + 16y = -22
--------------
19y = -13
y = -13/19

yes....he is correct

if y = -13/19, sub that in and solve for x
2x + 3y = 9
2(-13/19) + 3y = 9
-26/19 + 3y = 9 (multiply by 19)
-26 + 57y = 171
57y = 171 + 26
57y = 197
y = 197/57

check..
2x + 3y = 9
2(-13/19) + 3(197/57) = 9
-26/19 + 591/57 = 9
-78/57 + 591/57 = 9
513/57 = 9
9 = 9 (correct)

so x = -13/19 and y = 197/57 and Rodrigo is correct

Answer 10

oh ok

Answer 11

oh flutter

Answer 12

you know i didnt mean flutter

Answer 13

lol

Answer 14

but thank you very much miss texas

Answer 15

sorry it took so long...not the fastest at subtracting them....I do better with adding them

Answer 16

its completely ok