The school store sells erasers for $0.35 each and pencils for $0.15 each. Anthony spent $2.80 to buy a total of 12 erasers and pencils. How many erasers did Anthony buy?

5 erasers.

Step-by-step explanation:

0.35e + 0.15p = 2.80

e + p = 12

e = 12 - p

0.35(12 - p) + 0.15p = 2.80

4.2 - 0.35p + 0.15p = 2.80

4.2 - 0.2p = 2.80

-0.2p = -1.4

-0.2p/-0.2p = -1.4/-0.2

p = 7

e = 12 - 7

e = 5

the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.  

answer: .64

step-by-step explanation

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