How do you find the product of (a+5)(a-6)?

2 Answers
Apr 28, 2018

a^2 - a - 30

Explanation:

To solve this, we expand/distribute using FOIL:
enter image source here

As you can see in this image, the first thing we do is multiply the color(steelblue)"firsts":
a * a = a^2

Then the color(purple)"outers":
a * -6 = -6a

Then the color(peru)"inners":
5 * a = 5a

and finally the color(olivedrab)"lasts":
5 * -6 = -30

Now combine them all together:
a^2 - 6a + 5a - 30

We can still simplify the like terms. Let's color-code them:
a^2 quadcolor(red)(-quad6a quad+quad 5a) quad - quad30

Combine like terms and get the final answer:
a^2 - a - 30

Hope this helps!

Jun 30, 2018

a^2-a -30

Explanation:

color(blue)((a+5))color(green)( (a-6) )

Multiply everything in the right brackets (green) by everything in the left brackets (blue).

color(green)(color(blue)(a)(a-6) color(white)("ddd")color(blue)(+5)(a-6) )

Notice that the + sign followed the 5

a^2-6acolor(white)("dd")+5a-30

but -6a+5a is the same as -a giving.

a^2-a -30