. Find the product: (7x²-8y)(7x²+8y)

Question

anonymous · Answer

i got 49x⁴-56xy+56xy+64y²
49x⁴-112xy+64y²

hero · Answer

Hint: Difference of Squares

anonymous · Answer

Check that middle term:

"-56xy + 56xy"

anonymous · Answer

attachment

anonymous · Answer

Also (-8y)*(+8y) = ?

anonymous · Answer

attachment

anonymous · Answer

Try again. It is multiplication, not addition.

anonymous · Answer

ok im lost now

anonymous · Answer

Start over.

anonymous · Answer

$$\large (7x²-8y)(7x²+8y)=(7x^2)(7x^2)+(7x^2)(8y)+(-8y)(7x^2)+(-8y)(8y)$$

anonymous · Answer

multiply the first terms of each expression together...write down
then multipy the first term of the expression by the second term of the 2d exp...write down
then multiply the 2d term of the first exp by the first term of the 2d expression..write it down
finally multipy th 2s term of the 1st exp  by the 2d term in the 2s expression...write it down
simplify combining like terms and you have the answer.
or
FOIL   -----> First terms, Outside terms, Inside terms, Last terms  add them together after multiplying

anonymous · Answer

$$\left(7 x^2-8 y\right) \left(7 x^2+8 y\right)=49 x^4-64 y^2 $$