We are trying to solve for X. 72 degrees and the second angle are supplementary angles, meaning that they together equal to 180 degrees. 180 degrees minus 72 degrees is equal to 108 degrees so, 7x + 24 should equal to 108 degrees.
First off, we want to get rid of 24 so, to get rid of 24, we will subtract 24 from both sides which is: 7x = 84. Now, to get rid of the 7 from the X to just get X by itself, we will divide both sides by 7 which will equal to X = 12. So, X is equal to 12.
