Question

How do I solve:
x+y-6
x+2y=9

Please show the steps involved. Thank you.

Answer 1

Multiply 1st equation by -1 (first i think you are missing an equation sign there)
then add the equations together

Answer 2

x+y=6 => -x-y=-6
+(x+2y=9)
-------
0+y=3
y=3

Answer 3

y=3 and x+y=6 => x+3=6 => x=3

Answer 4

is that right x+y=6 or x+y=-6?

Answer 5

subtract 1st eqn fro 2nd eqn. Then u get
y=3
When applying the value of y in the 1st eqn
x+3=6
x=3

Answer 6

Can someone explain to me how -y + 2y = y?

Answer 7

-1+2=1

Answer 8

2-1=1

Answer 9

Ah, I see, thank you. Also, why did you change the first equation to all negative? Is there any extra steps I need to take in order to do that or do I just change it all to negative naturally?

Answer 10

i just wanted one of the variables to cancel when i added the equations together

Answer 11

so i seen the x's would cancel if one of them were negative

Answer 12

so if I multiply one term of an equation by -1 then I multiply all the terms of that equation by -1

Answer 13

Okay, thank you very much :)