Mathematic algebra

Question

A pool measuring 20 meters by 22 meters is surrounded by a path of uniform​ width, as shown in the figure. If the area of the pool and the path combined is 1368 square​ meters, what is the width of the​ path?

Answer 1

(20+x)(22+x) = 1368

440 +42x + x^2 = 1368

x^2 +42x - 928 = 0

(x+21)^2 = 928 +441 = 1369

x = -21 +sqr1369

(20+16)(22+16) = 36(38) = 1368

x = -21 +37 = 16

x = 16 meters