What types of problems can be solved using greatest common factor? what types of problems can be solved using three least common multiple?

The data represents the semester exam scores of 8 students in a math course. {51,91,46,30,36,50,73,80} what is the five-number summary?

X+y=-4 x-y=2 use elimination with adding and subtraction

Can some one explain how to slove specifically, what is the value of x? 0.9(x+1.4)-2.3+0.1x=1.6 enter the answer as a decimal in the box. x= ?