rectangular container is made up by cutting out four squares of side x cm from each corner of a piece of rectangular cardboard, 8cm by 6cm?

(a) Express the base area of the container in terms of x.
set the base area of the container is A cm^2
A = (8 - 2 x)(6 - 2 x) = 48 - 28 x - 4 x^2 (cm^2) .....Ans

(b)If the base area of the container is 24cm^2, show that x^2-7x+6=0
48 - 28 x - 4 x^2 = 24
4 (x^2 - 7x + 6) = 0
x^2-7x+6 = 0 ....Ans

(c) Solve x^2-7x+6=0
(x-7/2)^2=25/4
x-7/2= 5/2 or -5/2
x = 6 or 1
x=1 (x<3) ...Ans