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Popular >

factor r^2-81

Solution

factor

r^{2} - 81

Solution

(r + 9) (r - 9)

Solution steps

r^{2} - 81

Rewrite

81

as

9^{2}

= r^{2} - 9^{2}

Apply Difference of Two Squares Formula:

x^{2} - y^{2} = (x + y) (x - y)

r^{2} - 9^{2} = (r + 9) (r - 9)

= (r + 9) (r - 9)

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Frequently Asked Questions (FAQ)

What is factor r^2-81 ?
The solution to factor r^2-81 is (r+9)(r-9)