## Kellie13 3 years ago 4(x+y)=x-16

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1. Kira_Yamato

4(x+y) = x-16 4x+4y = x-16 3x+4y = -16

2. Kellie13

the rest of the equation I forgot to place in: -3(x-y)=y+10

3. richyw

So you have this system of equations$4(x+y)=x-16$$-3(x-y)=y+10$First solve the first equation for one of the variables$4x+4y=x-16$$4y=-3x-16$$y=-\frac{3}{4}x-4$Now plug that value into the second equation and solve for the second variable$-3x+3y=y+10$$-3x+2y=10$$-3x+2\left(-\frac{3}{4}x-4\right)=10$$-3x-\frac{3}{2}x-8=10$$\frac{-6-3}{2}x=18$$-\frac{9}{2}x=18$$x=-4$Now plug that value of x into either equation to solve for y.$4(x+y)=x-16$$4(-4+y)=-4-16$$-16+4y=-20$$4y=4$$y=1$So the solution is x=-4, y=1

4. richyw

oops, should be -1/

5. richyw

the second last line I dropped the negative it should say $4y=-4$$y=-1$So the solution is x=-4, y=-1

6. dpgreen

just to let you know, you dont only have to do the substitution process, you can also do elimination. 4(x+y)=x−16 −3(x−y)=y+10 distribute to get 4x+4y=x−16 -3x+3y=y+10 the subtract the common terms from each other to get final answer