The product of 4 and a number w is at most 51?

Cherie measures and records the lengths and sizes of the same style of a sandal found at a shoe store. which equation can be used to determine the approximate shoe size, s, for a foot length of x inches? s = x – 2 s = 2x – 10 s = x + 6 s = 2x + 4

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?