Question

Show all the work and factor the following: 9x^2-42xy+49y^2

Answer 1

`(3x-7y)^2`

Explanation:

`9x^2-42xy+49y^2\\3^2x^2-42xy+49y^2\\3^2x^2-2*3x*7y+49y^2\\3^2x^2-2*3x*7y+7^2y^2\\(3x)^2-2*3x*7y+7^2y^2\\(3x)^2-2*3x*7y+(7y)^2\\`

Using
`a^2-2ab+b^2=(a-b)^2`, factor the expression.

`(3x-7y)^2`

Answer 2

(3x-7y)^2

Explanation:

Rewrite it in the form a^2-2ab+b^2a

(3x) ​2 −2(3x)(7y)+(7y) ​2

Then

Use Square of Difference: a-b^2=a^2-2ab+b^2a−b

​2 =a​2 −2ab+b 2

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