Can you guys please help me with this? I will give brainliest and 20 points if you help me.

Step-by-step explanation:

1) a) equations: 3x+21 and 6x -60

b) value of x: 3x+ 21=6x-60  ( set them equal to each other because they are equal, then solve)

3x+21=6x-60

-3x=-81

x= 27

c) replace 27 in both equations to find the angle measure.

3(27)+21= 102

6(27)-60= 102

2) a) equations: 12x-18 and 8x+10

b) value of x:   12x-18=8x+10( set them equal to each other because they are equal, then solve)

12x-18=8x+10

4x=28

x= 7

c) replace 7 in both equations to find angle measure.

12(7) -18 = 66

8(7)+10= 66

angle measure: 66

3) a) equations: 7x+9 and 5x+3

b) value of x: to find value of x here, first know that the these two equations will add up to 180. So, set them up to be equal to 180.

7x+9+5x+3=180

Then solve.

12x+ 12=180

12x=168

x=14

c) angle measure: replace the 14 in the x of the two equations.

7(14) +9 = 107

5(14) +3= 73

add the two angle measure together to see if they add up to 180.

107 + 73 = 180 correct! :D

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.