Algebra 1 Special Products

Find the product of (x + 3)(x - 3)


x2 + 9
x2 - 9
x2 - 6x + 9
x2 + 6x + 9

Find the product of (2x - 5y)^2


4x^2 + 20xy + 25y^2
4x^2 - 25y^2
4x^2 - 20xy + 25y^2
4x^2 + 25y^2


Find the product of (3x + 7y)^2

9x^2 + 49y^2
9x^2 - 49y^2
9x^2 - 42xy + 49y^2
9x^2 + 42xy + 49y^2

Find the product of (3x + 7y)(3x - 7y)


9x^2 - 49y^2
9x^2 - 42xy + 49y^2
9x^2 + 42xy + 49y^2
9x^2 + 49y^2

Find the two products below. Compare and contrast, in complete sentences, the similarities and differences of the two.

(x + 4)(x - 4) and (x + 4)(x + 4)

these are no special formulae ..

(a+b)(a-b) = a^2 + ab -ab + b^2 (on expanding) = a^2 - b^2
Hence they say (a+b)(a-b) = a^2 - b^2

(a-b)^2 = (a-b)(a-b) = a^2 -ab -ab +b^2 (on expanding) = a^2 -2ab+ b^2
(a+b)^2 = (a+b)(a+b) = a^2 +ab +ab +b^2 (on expanding) = a^2 +2ab+ b^2

Using these, I think you can go ahead and solve the above questions.

Hope I made myself clear !!

All the Best !