Please help me with 7-9

Step-by-step explanation:

parallel lines means there are lines that go on forever and will never touch.

when there is a line going through both parallel lines, there are special rules that follow.

the same corner on both lines will equal the same amount, and the opposite corners should add to equal 180.

#8

they are comparing the same corner on both lines, so 3x=45. we are making the corners equal to each other.

divide by 3 on both sides and x= 15

#9 is the same, just make the corners equal each other.

2x+10=120

2x=110

x=55

#10 is slightly different since they are not asking for the same corner. they are showing the opposite corners. 80 is on one side and 2x+20 is on the other.

but since we know by putting those two corners together we will make a straight line of 180. so just add both corners together and make them 180

80+2x+20=180

100+2x=180

2x=80

x= 40

on the top left side it says 80 but the top right side should be 2x+20

bottom right says 2x+20 but the bottom left should be 80

this is how I need to see it in order to add to 180

5/12, or 5: 12

step-by-step explanation: