# algebra

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3x+5y=0 2x-5y=-9

idk how 2 solve it then graph it my teacher eont help me plzz help

• algebra -

I assume you need to solve these equations simultaneously ?

3x + 5y = 0
2x - 5y = -9

Solving by elimination method. The object is to eliminate one of the variables, either x or y.

Since you have +5y in the first equation and -5y in the second equation, you ADD the two equations.
This is because +5y + -5y = 0.

3x + 5y = 0
2x - 5y = -9
5x + 0 = -9
5x = -9
Divide both sides by 5
x = -9/5

To find y, substitute x = -9/5 in either equation and solve for y.
3x + 5y = 0
x = -9/5
3(-9/5) + 5y = 0
-27/5 + 5y = 0
-27/5 + 27/5 + 5y = 27/5
5y = 27/5
Divide both sides by 5
y = 27/5 /5
Multiplying the numerator by the reciprocal of the denominator is the same as dividing.

y = 27/5 * 1/5
y = 27/25

I'll leave the check to you.
x = -9/5, y = 27/5

• algebra -

o ok ty

• algebra -

You're welcome.

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