math problem!!!

Question

Solve the system of linear equations by substitution.

x=16−4y

3x+4y=8

Answer 1

Step 1) Add or subtract to isolate y or x, but in this case x equation is given.

Step 2) Substitute x in the 2nd equation: 3(16 - 4y) + 4y = 8

Step 3) Distribute and multiply 3 to 16 and 4y: 48 - 12y + 4y = 8

Step 4) Simply the equation by making it one term which means add -12y + 4y: 48 - 8y = 8

Step 5) Subtract 48 by both sides so we can single the y term: -8y = 8-48 -> -8y = -40

Step 6) divide -8 by both sides: y = -40/-8 = 5

Step 7) go back to the x equation and plug in 5 for y: x = 16 - 4(5)

Step 8) Solve for x: x = 16-20 = -4

Answer 2

x=16−4y

3x+4y=8

plugin 16-4y in the place of x in the second equation

3(16−4y)+4y=8

48-12y + 4y =8 combine like terms

48-8y =8 subtract 48 both sides

48-48-8y= 8-48

-8y= -40 divide -8 both sides

-8y = -40

-8 -8

y= 5

Now plug in 5 in the place of y in any of the equation to find x

x=16−4y 3x+4y=8

x= 16-4(5) 3x+ 4(5) =8

x= 16-20 or 3x+ 20=8

x= -4 3x+20-20 = 8-20

3x=-12

3x = -12 x= -4

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