SOLUTION: A strip of uniform width is to be cut off of both sides and both ends of a sheet of paper that is 21 inches by 4 inches, in order to reduce the size of the paper to an area of 38 s

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: A strip of uniform width is to be cut off of both sides and both ends of a sheet of paper that is 21 inches by 4 inches, in order to reduce the size of the paper to an area of 38 s      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 501488: A strip of uniform width is to be cut off of both sides and both ends of a sheet of paper that is 21 inches by 4 inches, in order to reduce the size of the paper to an area of 38 square inches. Find the width of the strip.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Let strip width be = x
21-2x will be the length after cutting
4-2x will be the size after cutting
(21-2x)(4-2x)=38
84-42x-8x+4x^2=38
4x^2-50x+46=0
Find the roots of the equation by quadratic formula

a= 4 ,b= -50 ,c= 46

b^2-4ac= 2500 + -736
b^2-4ac= 1764
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-12%2B21%29%2F%2812%29
x1=( 50 + 42 )/ 8
x1= 11.5
x2=( 50 -42 ) / 8
x2= 1
logically width = 1 "