Question

looking for the substitution solution for this question
2x-y=4
5x-2y=10

Answer 1

Isolate \(\rm y\) in the first equation.

Answer 2

so that would be 2x=4 which is x=2 right

Answer 3

...?

Answer 4

negative wrong
this is what I thought I did add 2x+5x 2y-y 10+4

Answer 5

so that would be 7x-y=14

Answer 6

nubeer you love me again lol

Answer 7

Isolating means:

2x - y = 4

Adding y to both sides gives:
2x = y + 4

Subtracting 4 from both sides gives:

2x - 4 = y

So now that you know what y is, "substitute" it in the second equation.

Answer 8

so y is 2

Answer 9

then on the second equation I would do 5x-2y+2y+10 + 2y

Answer 10

No.

Plug in y = 2x - 4 to

5x - 2y = 10
5x - 2(2x - 4) = 10

Answer 11

5x-4x-4=10

Answer 12

1x-4=10

Answer 13

x=14

Answer 14

You made a mistake there:

5x-4x >>>-4<<< =10

5x - 2(2x - 4) = 10

5x - (2*2x) - (2*-4) = 10

Answer 15

5x-4x--8=10

Answer 16

x=2

Answer 17

Yep. Can you find y now?

Answer 18

isnt it 4

Answer 19

muntoo

Answer 20

2x-y=4

x=2, so
2(2)-y=4

Now do the rest.

Answer 21

2x-y=4 ................ eqn 1
5-2y = 10 ...............eqn 2

solve simultanously

x = 4+y/2 ............. eqn 3

Now sub eqn 3 into 2

5(4+y/2) - 2y = 10
20y/2 - 2y = 10
20y - 2y = 20
18y = 20
y = 20/18

thus

y = 10/9

now sub y into eqn 1

x = 4 + (10/9)/2
x = (14/10)/2
x = 28/10

thus

x = 14/5

so

x = 14/5

y = 10/9

Answer 22

4-y=4
add 4 to both sides and y=8

Answer 23

@The_G.O.A.T Your second equation is wrong.

http://www.wolframalpha.com/input/?i=2x-y%3D4%2C+5x-2y%3D10

Answer 24

(I mean you copied the second equation from the given wrong.)

Answer 25

yeah kust left out the x but it is back in further down

Answer 26

just

Answer 27

@bigmommatiad Adding 4 to both sides gives

4 - y = 4
4 - y + 4 = 4 + 4

Which is

4 + 4 - y = 8
8 - y = 8

Answer 28

crud

Answer 29

so then you would subtract the 4 and that would be 0

Answer 30

so x=2 and y=0

Answer 31

@The_G.O.A.T Equation 3 is wrong.

2x-y=4
2x = 4 + y
x = 2 + y/2

Answer 32

@bigmommatiad Yes.

Answer 33

awesome can you help me with another problem

Answer 34

i would not say its wrong just left it all over 2

Answer 35

a barrel containes 183 gallons and they are draining at 9 gallons a minutes
write equation that models the number of gallons, g, after the t minutes
the model the given situation is ??

Answer 36

would it be like this 183/9=??

Answer 37

They want you to write an equation.

You start off with 183 and lose 9 every minute. So:

gallons_left = 183 - 9 * minutes