Harlon wrote the equation uppercase A = 18 (x squared + 1) to find the area of a rectangle that has a length of x squared + 1 and a width of 18. He solved for x and got x = plus-or-minus StartRoot StartFraction uppercase A Over 18 EndFraction minus 1 EndRoot Which of the following is an equivalent equation for x? x = plus-or-minus StartRoot StartFraction uppercase A minus 18 Over 18 EndFraction EndRoot x = plus-or-minus StartRoot StartFraction uppercase A + 18 Over 18 EndFraction EndRoot x = plus-or-minus StartRoot uppercase A minus 36 EndRoot x = plus-or-minus StartRoot uppercase A + 36 EndRoot