multiplying polynomials

Question

I need help solving. please help. show me step by step. THANKS(: (a-8)(a+5)

Answer 1

Hi Summyr;

(a-8)(a+5)

We are going to FOIL...

FIRST...(a)(a)=a²

OUTER...(a)(5)=5a

INNER...(-8)(a)=-8a---note the negative sign as the equation involves subtraction.

LAST...(-8)(5)=-40---note the negative sign as the equation involves subtraction.

 

a²+5a-8a-40

Let's combine like terms...

a²-3a-40

Note that the figure with the exponential, a², comes first.  The figure with the coefficient, -3a, is second.  The constant, -40, is last.  This is standard hierarchy.