Find the greatest common factor of 21 and 10

The water has been on the stove y=9.5x+62.1 after how many minutes will the tempature be 138.1 f

(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 .

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10