The length of rectangle is 4cm less than thrice the width. When the length increased by 7 cm and the width is decreased by 2 cm, the perimeter equals 90 cm. Find the length and width of the rectangle.
Let, the width be 'x' and length be 3x-4.
After increasing the length by 7cm,
= 3x-4+7 = 3x+3
After decreasing the width by 2cm
= x-2
Therefore, the perimeter of the rectangle=90cm
2(l+b)=90
2(3x+3+x-2)=90
2(4x+1)=90
8x+2=90
8x=90-2
8x=88
8x/8=88/8
x=11
Length of the rectangle= 3x-4
=3x11-4
=29cm
Width of the rectangle=11cm