Can you help me with these math problems?

Uhm ok, the first two people have it kind of half right… The FOIL method is the best way to do this, but the answer to the first one is not 4b + 20…

A. (b + 8)(b + 2)

1. First: b x b = b2 (b times b = b squared)
2. Outer: b x 2 = 2b (b times 2 equals 2b) 3: Inner: 8 x b = 8b (8 times b equals 8b) 4: Last: 8 x 2 = 16
3. Combine like terms: b2 + 2b + 8b + 16 = b2 + 10b +16

B. (x - 4)(x - 9)

1. First: x·x= x2
2. Outer: x·-9 = -9x (x times negative 9 equals negative nine x)
3. Inner: -4·x = -4x 4 Last: -4 x -9 = 36 (negative 4 times negative four equals positive 36)
4. Combine like terms: x2 + (-9x) + (-4x) + 36 = x2 - 13x + 36

C. (p + 4)(p2 + 2p - 7) - ok so same basic principle

1. p x p2 = p3 (p cubed)
2. p x 2p = 2p2 (2 p squared)
3. p x -7 = -7p
4. 4 x p2 = 4p2 (4p squared)
5. 4 x 2p = 8p
6. 4 x -7 = -28
7. Combine like terms: p3 + 2p2 + 4p2 + (-7p) + 8p - 28 = p3 + 6p2 + 1p -28

The important thing is to keep track of the pluses and minuses

you times them

1.(b + 8)(b + 2) = bxb + bx2 +bx8 + 8x2 = B2 +2B + 8B + 16 = B2 + 10B +16

2. (x - 4)(x - 9) = = X x X - 9xX - 4xX +4x9 = X2 - 9X - 4X + 36 = X2 - 13X +36

etc…

LeAnne’s gas tank was 7/8 full. After she drove 150 miles, the tank was 1/3 full. What fraction of a tank of gas did she use on her trip?

Here’s another explanation that I found on the net that may help you.

A technique for distributing two binomials. The letters FOIL stand for First, Outer, Inner, Last. First means multiply the terms which occur first in each binomial. Then Outer means multiply the outermost terms in the product. Inner means multiply the innermost two terms. Last means multiply the terms which occur last in each binomial. Then simplify the products and combine any like terms which may occur.

Example: (x + 2)(x + 5) = x·x + x·5 + 2·x + 2·5

                     First Outer Inner  Last 

                    = x2 + 7x + 10

I think you just combine like terms for number 1. So, b + b = 2b and 8 + 2 = 10.