What is the length of PM if PM=4x-12 and MR=-2x+24?

Answer 1

This problem is missing some additional information. But as given,

PM=4x-12. Since lengths are positive 4x-12>0, 4x>12, x>3

MR=-2x+24 > 0, 2x<24, x<12

Put that together, x<12 and x> 3 gives

3<x<12, While not a unique solution, it narrows the value of x to a limited range. A guess might be the average, or about 6.5

If some additional info were known, such as maybe PM=MR, then

4x-12 = -2x+24

6x = 36

x = 6