Question

solve the system of equations 2x+y=11

Answer 1

Do you have the other equation?

Answer 2

oh no hold up, that does not fit

Answer 3

She has another equation with it...

Answer 4

x-y=4 is the other equation with it.

Answer 5

Solve for y first...

2x+y=11
-2x -2x

y=11-2x

Now plug in 11-2x in for y in the other equation...

x-y=4

x-(11-2x)=4

Distribute...

x-11+2x=4
+11 +11

x+2x=15

3x=15

Divide both sides by 3

3x/3=15/3

x=5

Plug in any equation...

x-y=4

(5)-y=4
+5 +5

-y=9

Divide by -1 to get y to be a positive number...

-y/-1=9/-1

y=-9 and x=5

Answer 6

Substitution is the best method for this.
Change x-y+4 to y=x-4 and plug in
2x+x-4=11
3x-4=11
3x=15
x=5

and if you plug that value in,
2(5)+y=11
y=1

so (5,1)

Answer 7

would substitution method be the best also for this one to:
5x-2y=28
3x+47=22

Answer 8

No, the elimination would be best. Do you want me to work it out for you?

Answer 9

I think there is a mistake in the other equation that I did...

Answer 10

hey did you mean 4y or 47?

Answer 11

not 47 4y
yes please

Answer 12

okay. I will work it out as 4y

Answer 13

yes

Answer 14

since 4 is 2 times 2, multiply 2 with every thing on top equation :)

5x(2)-2y(2)=28(2)
which would be
10x-4y=56

then,

10x-4y=56
(+) 3x+4y=22
___________________
13x=78

x=6

Plug in on either original equation. (I will go with bottom one)
3(6)+4y=22
18+4y=22
4y=4
y=1

So (6,1)

check;

5(6)-2(1)=28
30-2=28

3(6)+4(1)=22
18+4=22

DONE!!!! :D

Answer 15

thanky ou!!!!