How do you evaluate $(5a + 1) ( 3a - 8)$ ?

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Answer 1 · 2018-03-20T09:40:07

$15a^2-37a-8$

$(5a+1)(3a-8)$
$5a(3a-8)+1(3a-8)$ [Multiply each term with the other]
$15a^2-40a+3a-8$
$15a^2-37a-8$

Answer 2 · 2018-03-20T09:42:54

Apply FOIL rule (first, outer, inner, last) $(5a+1)(3a-8)=5a*3a+5a*(-8)+3a*1+1*(-8)$
= $15a^2-37a-8$

Apply FOIL rule (first, outer, inner, last)

Try an example with (6+2)(4-2) = 8 x 2 = 16

So we apply foil rule

$6*4+6*(-2)+2*4+2(-2)=24-12+8-4=16$

How do you evaluate (5a + 1) ( 3a - 8)(5a + 1) ( 3a - 8)?