Question

when $f(x) = 9x^2 - x - 1$, evaluate $f(-4)$
$f(-4) = \boldsymbol{\square}$
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Explanation:

Step1: Substitute $x=-4$ into $f(x)$

$f(-4)=9(-4)^2 - (-4) - 1$

Step2: Calculate the squared term

$(-4)^2=16$, so $9\times16=144$

Step3: Simplify the linear terms

$-(-4)=4$, so $f(-4)=144 + 4 - 1$

Step4: Compute the final sum

$144+4=148$, $148-1=147$

Answer:

147