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How do you find the product of #(r+1)(r-2)#?

Answer 1

Eli Assouline

#r^2-r-2#

F.O.I.L.

First
Outer
Inner
Last

FOIL is just a way of factoring

So, start out by multiplying the First terms together in each set of parenthesis #rxxr=r^2#

Outer: multiply the outer most terms in each set of parenthesis #rxx-2=-2r#

Inner: multiply the inner terms of the set of parenthesis #1xxr=r#

Last: multiply the last terms of each set of parenthesis together #1xx-2=-2#

Altogether, the equation would look like: #r^2-2r+r-2#

(I just broke it down so that it was easier to see each step)

Next, combine like terms, which would be #-2r# and #r# #-2r+r=-r#

And the final equation looks like: #r^2-r-2#

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Answer 2

Nathan Axel

To find the product of (r+1)(r-2), you use the distributive property. First, multiply each term in the first expression by each term in the second expression. Then, combine like terms if necessary. So, (r+1)(r-2) simplifies to rr + r(-2) + 1r + 1(-2). This results in r^2 - 2r + r - 2. Simplifying further, you get r^2 - r - 2.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.