Answer:
x = 55
Step-by-step explanation:
what I think is written there :
2x + 6
x + 9
it is important to recognize that both lines are parallel and are therefore cutting the third line with the same angles.
so, the large angle at one cutting line is the same large angle at the second cutting line. and the same for the small angles.
now, a line (one one side) stands for 180 degrees "turning". this is like a line in the ground and a stick laying on it. keeping one end of the stick on the ground you can lift the other end up, up, up until the stick stands upright. that is 90 degrees. and then you can keep turning the stick around the end still on the ground, and the stick will (more on the other side) get lower and lower to the ground again, until the stock is laying flat on the ground again.
this is then another 90 degrees, and you did a full 180 degree turn.
so, all angles along a line have to add up to 180 degrees.
in other words, the small angle plus the large angle must be in total 180 degrees.
=>
2x + 6 + x + 9 = 180
3x + 15 = 180
3x = 165
x = 55
