How do you factor by grouping $8r^3 - 64r^2 + r -8$ ?

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Answer 1 · 2018-04-25T01:11:18

$(8r^2+1)(r-8)$

In grouping, separate the first two terms (in this case, $8r^3$ and $-64r^2$ ) from the second two terms (in this case, $r$ and $-8$ ):

$(8r^3-64r^2)+(r-8) rarr$ Factor out the GCF from each of the pairs in the parentheses

$8r^2(r-8)+1(r-8) rarr$ Combine the $8r^2$ and $1$

$(8r^2+1)(r-8)$

How do you factor by grouping 8r^3 - 64r^2 + r -88r^3 - 64r^2 + r -8?