The area of a rectangle is given by A = x2 + 4x – 5. Find the value of x if the total area of the rectangle is equal to 7 square units.
a) x = 7
b) x = 2
c) x = 5
d) x = 1

Question

The area of a rectangle is given by A = x2 + 4x – 5. Find the value of x if the total area of the rectangle is equal to 7 square units. 
 a)  x = 7 
 b) x = 2 
 c) x = 5 
 d)  x = 1

anonymous · Answer

$x^2+4x-5=7 => x^2+4x-12=0$
Then solve for $x$

anonymous · Answer

lets equate the equation to 7, since the area is equal to 7.

x^2 + 4x -5 = 7
x^2 + 4x -5 -7 = 0
x^2 + 4x -12 = 0

Now since this is a 2 degree polynomial equation, you have to solve for x using the quadratic equation 

x = 2 and x = -6, since x cant be negative its x = 2;

anonymous · Answer

Thanks AS alway @javawarrior, & @Omniscience

anonymous · Answer

(:

anonymous · Answer

quadratic formula* 
and your welcome :)