Step-by-step explanation: Because angles on a straight line add up to 180 degrees, 4x+6x=100 would give you the desired x. Solving this, x=18. Multiplying x by 4 gives 72. Hope this helps! (Could I please have brainliest?)
They have essentially divided up the line 2 different ways, into 2 parts and into 10 parts. The 2 parts is from 1 and 2 and then the 10 parts is because of the ratio 4-6. The 2 parts are not equal because one of them is 4 parts of the line and the other is 6, if we put that together we get the 10 equal parts of the line. A line is equal to 180 degrees meaning that we can divide that my 10 to figure out how much each part is equal to 180/10 is 18 so each of the 10 parts is equal to 18. We are looking for <1 which it says is equal to 4 parts so we will multiply 4 by 18 to get how much it is. 4 times 18 is 72 so the answer is A
I hope this helps and please don't hesitate to ask if there is anything still unclear!
