Question

Solve the system of equations:
x-y=4
x-2y=10

Answer 1

from eqn 1, x = 4+y
plugging in the value of x to eqn 2
4+y-2y=10
-y=6
y=-6
and x = 4-6
x=-2

Answer 2

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

y = y

-2(x-4) = 10 -x

-2x+8 = 10 -x

x = -2
y= -6

Answer 3

thanks

Answer 4

use substitution

rearrange first formula to either get x =
or y =

lets choose x =

so you would get

x = 4 + y

now use this in your second equation everywhere you see x just replace it with that
so your second equation

x - 2y = 10

replace the x with 4 + y
so

4 + y - 2y = 10

bring all the numbers to one side and variables on the other
remember bringing a number to the otherside changes its value e.g. briging 4 to the other side will change it to - 4

so

y - 2y = 10 - 4

is

y = 6

Answer 5

thats one way
you could multiply bottom equation by -1 (or top)
and then add the equations

Answer 6

dont forget to click good answer

Answer 7

x - y = 4
-x + 2y = -10
-------------------
0 +y=-6
=>y=-6

Answer 8

and we can plug in y=-6 into either equation given and solve for x

Answer 9

sorry the answer is y = -6 i made a mistake if there was a edit feature i would have changed that but otherwise i have to rewrite whole thing again

y - 2y = 10 - 4

will give you

-y = 6

flip them around remember the rule about bringing something to the other side changes their value to the opposite
so

6 = y

Answer 10

arghhh made it again the mistake !!

-6 = y

Answer 11

\[x -(-6)=4 => x+6=4 => x=4-6=-2\]