Answer:
-48x²-116xy-56y² or
-4(12x²+29xy+14y²)
Step-by-step explanation:
A.
(7x+9y)(7x+9y)=
49x²+126xy+81y²
(x+5y)(x+5y)=
x²+10xy + 25y²
subtracted from means
x²+10xy + 25y² goes first
(x²+10xy + 25y²) - (49x²+126xy+81y²)
- (49x²+126xy+81y²) means
-1 times (49x²+126xy+81y²)
-1*(49x²+126xy+81y²) = -49x²-126xy-81y²
x²+10xy+25y²-49x²-126xy-81y²
-48x²-116xy-56y²
or
B.
sometimes its good to use real numbers
use x = 0 y = 1
(9)(9) is subtracted from (5)(5)
81-25=56
