The length of a line segment is and its endpoints are (5,1) and (x,-3). what is the solution set for x?

To solve the length of a line, use the distance formula (which is also the pythagorean theorem). In this case, it's (5-x)^2 + (1+3)^2 = 20. 

Simplify that to (5-x)^2 + 16 = 20,
so (5-x)^2 = 4
So 5-x = 2 or -2,
so x = 3 or 7.

On monday,mrs.wise bought 3 lbs of apples at $4per lb= 4*3=$12on tuesday ,20%off and she buy 5 lbs of apples = $4-20%=3.20*5lb=$16example: other wise when she buy 5lbs on monday she have to spend 4*5=20