Problema Solution
The width of a rectangle is 7 centimeters less than twice it's length. It's area is 30 square centimeters. Fund the dimensions of the rectangle
Answer provided by our tutors
let lenght be L,
thus width=2L-7
area 30=L(2L-7)=2L2-7L
2L2-7L-30=0
2L2-12L+5L-30=0
2L(L-6)+5(L-6)=0
(2L+5)(L-6), so L=6 or L=-5/2, thus L=6 (positive answer)
so lenght=6cm and width=2(6)-7=5cm