Algebra Help Substitution ?

Question

20. Find the solution to each system of equations.

y = -x + 12

y = 2x - 6

a. infinitely many

b. no solution

c. (6, 6)

d. (6, -6)

and

29.Find the solution to each system of equations.

y = 2x + 6

y = -x -3

a. (3, 0)

b. (-3, 0)

c. infinitely many

d. no solution

Thanks

Answer 1

20. y = -x + 12

      y = 2x - 6

Since both equations equal y, you could just make them equal each other like this:

-x + 12 = 2x - 6

Then solve for x.

3x = 18

x = 6

Now substitute x into one of the equations to find y. I'm going to use the first one.

y = -x + 12

y = -(6) + 12

y = 6

So since a coordinate point is set up like this, (x,y), just substitute x and y.

Answer: c. (6,6)

29. y = 2x +6

     y = -x - 3

Do this the same way as the first one.

2x + 6 = -x - 3

Solve for x.

3x = -9

x = -3

Now substitute x into one of the equations to find y.

y = -x - 3

y = -(-3) - 3

y = 3 - 3

y = 0

Answer: b. (-3,0)

By the way, learning systems of equations is EXTREMELY important, so make sure you learn it.

Answer 2

OMG are you being serious? This is so easy do it yourself. What an ******* cheater you can't post your homework online and get answers. And wtf is this 'thanks for your help' at the end of the page. If I give you the answers HOW THE h**l IS THAT HELP, that is me giving you the answer. Go do your homework, at least post what you thought was the answer and then ask for help

Answer 3

20.

-x+12 = 2x-6

-x-2x = -6-12

-3x = -18

3x = 18

x = 6

y= -x+12

y= -6+12

y= 6

c. (6,6)

2x+6 = -x-3

2x+x = -3-6

3x = -9

x = -3

y= 2x+6

y= 2*(-3)+6

y= -6+6

y= 0

b. (-3,0)