Question

24. x4 -11x2 - 80 factorise​

Answer 1

$\large{\sf{x⁴~-11x²~-~80}}$

Here we need to find 2 numbers whose sum is equal to 11x² & multiplication results in 80x⁴

$\large{\sf{x⁴~-16x²~+~5x²~-80}}$

$\large{\sf{\underbrace{x⁴~-16x²}~+~\underbrace{5x²~-80} }}$

Taking common

$\large{\sf{x²~(x²~-16)~+5~(x²~-~16)}}$

$\large\pink{\sf{Factors~→(x²~+~5) (x²~-~16) }}$

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$\red{\sf\frak{-~shashi1979bala}}$