Ms. Swanson asked the question, “How does knowing the fact 6 × 5 6×5 help you find 60 × 500 60×500?" Maria answered, “I know 6 × 5 6×5 is 30 30. Now all I have to do is count the zeros and I get 3 , 000 3,000." Use place value understanding to explain why her answer is incorrect.

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify

1. perpendicular

2. parallel

3. perpendicular

delaney would like to make a 5lb nut mixture that is 60% peanuts and 40% almonds.

she has several pounds of peanuts and several pounds of a mixture that is 20% peanuts and 80% almonds.

let 'p' represent the number of pounds of peanuts needed to make the new mixture, and  

let 'm' represent the number of pounds of the 80% almond-20% peanut mixture.

:

p + m = 5

therefore

m = (5-p)

write an equation based on the percent of peanuts

1p + .2m = .6(5)

replace m with (5-p)

p + .2(5-p) = .6(5)

p + 1 - .2p = 3

p - .2p = 3 - 1

.8p = 2

p = 2/.8

p = 2.5 lbs of peanuts required

then

5 - 2.5 = 2.5 lbs of the peanut/almond mixture required

:

a) what is the system that models this situation?

p + m = 5

1p + .2m = .6(5)