SOLUTION: A rectangle is 4cm longer than it is wide. If it is x cm wide and has an area of 77cm squared. Form an equation in x and solve it to find the dimensions of the rectangle

Algebra ->  Rectangles -> SOLUTION: A rectangle is 4cm longer than it is wide. If it is x cm wide and has an area of 77cm squared. Form an equation in x and solve it to find the dimensions of the rectangle       Log On


   

Question 957389: A rectangle is 4cm longer than it is wide. If it is x cm wide and has an area of 77cm squared. Form an equation in x and solve it to find the dimensions of the rectangle
Answer by satyareddy(3) About Me  (Show Source):
You can put this solution on YOUR website!
width=x cm,
Let length be l cm
l-x=4 cm =>l = 4+x---------(1)
lx=77
substituting (1) in lx=77
(4+x)x=77
4x+x^2=77
x^2+4x-77=0
x^2+11x-7x-77=0
x(x+11)-7(x+11)=0
(x+11)(x-7)=0
x=-11,7
since width cannot take negative value x=7
substituting x=7 in (1)
l=4+7=11