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12 votes
12 votes
5x+5y=0
-8x+y=36
I need help with this.

User Patridge
by
2.5k points

2 Answers

25 votes
25 votes

Answer:

x= -4, y = 4.

Explanation:

first, divide the first equation by its G.C.D (5), to obtain its simplest form.

5x/5 + 5y/5 = 0/5 to obtain x + y = 0.

Then, find the value of y by rearranging the second equation.

y = 36 + 8x. (Rem; when 8x moves to the other side of the equation, it changes the sign)

Now substitute the value of y (36 + 8x) in the first equation which is x + y = 0.

x + 36+8x = 0

Put like terms together.

36 + 9x = 0

move 9x to the other side and change its sign.

36 = -9x

divide both sides by 9,

x = -4.

Lastly, find the value of y by replacing the value of x in either equation.

-8(-4) + y = 36

32 + y = 36

rearrange to obtain

y = 36 - 32

y = 4.

User Chris Jaynes
by
3.0k points
12 votes
12 votes
first because 5x+5y=0 you can factor the 5
from equation so:
5(x+y) =5 (0) => x+y=0
and by solving for × using elimination method
-8x+y=36
x+y=0
by subtracting both x and y we get
-9x=36 => x=-4
by inputing × into the "x+y=0" equation so we get:
-4+y=0 => y=4
User Tengiz
by
2.7k points