Question

The length of a rectangle is greater than it's breadth by 18 centimetre . If both length and breadth are increased by 6 centimetre, the area of the new rectangle formed is 168 sq.cm more than the original rectangle find the length and breadth of the original rectangle​

Answer 1

let the breath be x cm

length will be x +18cm

by increasing both by 6cm,

new breath=(x+6)cm

new length=(x+24)cm

area=l×b

168=(x+6)(x+24)

168=x(x+24)+6(x+24)

168=x^2+24x+6x+144

x^2+30x+144-168=0

x^2+30x-24=0

further is simple middle term splitting