The length of a rectangle is 5 centimeters less than twice its width. the perimeter of the rectangle is 26 cm. what are the dimensions of the rectangle?
a)length = 5 cm; width = 5 cm
b)length = 6 cm; width = 7 cm
c)length = 4 cm; width = 9 cm
d)length = 7 cm; width = 6 cm

Let w and l be the length and height of the rectangle.

We know that:

Substitute the first equation in the second:

Use the first equation to compute the length:

So, length = 7 cm; width = 6 cm

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.