Question

Please help me find the vaule of X and Y!!
5x-2y=-15
3x+8y=37

Answer 1

step1; multiply equation 1 with 4
step2; add the two equations

Answer 2

?

Answer 3

when you do as @Kanwar245 has said you get

20x - 8y = -60
and
3x + 8y = 37

when he said add the 2 equations...look what happens when you do that...the -8y and 8y cancel....all you have left is the x's so that's how you solve for x

23x = -23
x = -1

if you wanted to solve for y first
what you want to do ...is multiply the whole top equation by -3
and then multiply the whole bottom equation by 5

this will give you

-15x +6y = 45
15x+40y=185

now when you add the 2 equations ...the x's cancel out...and all you have is a y

46y = 230
y = 5

you have your x and your y :)

Answer 4

thank you SO much! I have another equation to ask, if thats okay? What's the value of X and Y if the equation is: -x+y=1
x+y=11

Answer 5

no problem :)

and heres a substitution question

we have

-x + y = 1
x + y = 11

solve for y in the first equation

-x + y = 1
add x to both sides...makes this become

y = x + 1

now you have what "y" equals right? plus that into your second equation where you see a y

x + y = 11
x + (x + 1) = 11

subtract 1 from both sides

x + x = 10

x+x = 2x right?

2x = 10
divide both sides by 2

x = 5

so now we have x...plug that into the 1st equation wherever you see an "x"

-x + y = 1
-(5) + y = 1

-5 + y = 1
add 5 to both sides

y = 6

plug BOTH numbers into the second equation to check

x + y = 11
(5) + (6) = 11
5 + 6 = 11
11 = 11? yes it does

so x = 5 and y = 6 :)

Answer 6

and also you can plug both numbers back into the first equation as well

-x + y = 1
-(5) + (6) = 1
1 = 1...yes again....so we have the correct solution :)

Answer 7

you're awesome and totally a lifesaver! thank you thank you thank you (:

Answer 8

lol anytime :) feel free to fan me and message me if you need help with anything else :)

Answer 9

will do (: