Question

Please help. Don't understand this.

Answer 1

V=lwh
198 = 3(x-1)(x-4)
(x-1)(x-4)=x^2-5x+4
3(x^2-5x+4)
= 3x^2-15x+12

3x^2-15x+12=198

Subtract 198 from both sides

= 3x^2-15x-186 

use Quadratic formula <-- google if you forgot it

=10.761355820929152 and a different number which is negative, so reject it
Round it to 10.76
x=10.76