How do you solve the system of equations 9x + 8y = 09x+8y=0 and 3x - 8y = - 483x−8y=−48?

2 Answers
Cri007
Apr 19, 2017

(-4, 9/2)(−4,92)

Explanation:

Since there is a -8y−8y and a +8y+8y, let's add the equations.

9x+8y=09x+8y=0
3x-8y=-483x−8y=−48

12x=-4812x=−48
x=-4x=−4

Plug this in, and:
9(-4)+8y=09(−4)+8y=0

8y=368y=36

y=9/2y=92

Thus, our answer is (-4, 9/2)(−4,92).

ali ergin
Apr 19, 2017

x=-4" , "y=4.5x=−4 , y=4.5

Explanation:

9x+8y=0" , "(1)9x+8y=0 , (1)
3x-8y=-48" , "(2)3x−8y=−48 , (2)

"let us sum the equation (1) and (2)."let us sum the equation (1) and (2).

9x+cancel(8y)+3x-cancel(8y)=0-48

12x=-48

"let us divide both sides of equation by 12."

(cancel(12)x)/cancel(12)=(-48)/12

x=-4

"let us write x=-4 in the equation (1)."

9*(-4)+8y=0

-36+8y=0

8y=36

(cancel(8)y)/cancel(8)=36/8

y=36/8=9/2=4.5

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