Use foil method
\left(3x\right)\left(3x\right)+3x\left(1\right)+\left(-1\right)\left(3x\right)+\left(-1\right)\left(1\right) 9x^2+3x-3x-1
Combine like terms
Answer\:=\:9x^2-1
Frequently asked questions (FAQs)
What is the criteria for the signs of equality in triangles?
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In triangle ABC, if AB = 5cm, BC = 7cm, and AC = 8cm, is triangle ABC congruent to triangle XYZ with XY = 8cm, YZ = 5cm, and XZ = 7cm?
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What is the cosine of an angle in a triangle with side lengths 4, 7, and 9?