In DEF the measure of F is 90

Solve: 3x+y=6 4x-2y=18 show all work !

(least common multiples) the answer that i had in the 1st step was lcm of airline tickets sold=72. idk if that even matters but just in case. ! three co-workers are busy selling airline tickets over the phone. in an 8-hour day, charles can sell 8 airline tickets, ann can sell 9 airline tickets, and michelle can sell 6 airline tickets. step 2 of 2: what is the smallest number of 8-hour days needed for each of them to achieve the same number of sales? it takes charles . it takes . it takes .

Plz hurry evaluate the expression a+b where a=8 and b=19