Question

if possible dimensions of a rectangle are (x+5)& (x-4) then area of the rectangle is

a) x²-2x + 20 .

b) x² + x - 20.
+
c) x² + x + 20.

d) x²+2x + 20.​

Answer 1

Step-by-step explanation:

l*b= (x+5)(x-4) = x²+(5-4)x+5(-4)= x²+x-20

Option b is correct.

and here the identity used is( x+a)(x+b) = x²+(a+b)x+ab