Kim is sending postcards to her family. Each postcard is rectangular with an area of 12 square inches, and the length is 4 inches more than the width. Find the length and width of each postcard. If x represents the width of each postcard, select all of the equations that could be used to solve this problem.
Accepted Solution
A:
Let x-------------> the width of each postcard y-------------> the the length of each postcard
we know that A=12 in² A=x*y-------> 12=x*y-------> equation 1 y=x+4-----> equation 2 I substitute 2 in 1 12=x*y----------> 12=x*[x+4]------> 12=x²+4x------> x²+4x-12=0 x²+4x-12=0
using a graph tool----> to resolve the second order equation see the attached figure
the solution is x=-6----> is not solution x=2 in y=x+4----> y=2+4-----> y=6 in
the answer is the length of each postcard is 6 in the width of each postcard is 2 in