Gianna and her children went into a movie theater and she bought $77.50 worth of bags of popcorn and pretzels. each bag of popcorn costs $6.50 and each pretzel costs $4.75. she bought a total of 13 bags of popcorn and pretzels altogether. determine the number of bags of popcorn and the number of pretzels that gianna bought.

4 pretzels and 9 popcorn

Step-by-step explanation:

x=popcorn and y=pretzels

x+y=13 solve for x

x=13-y

6.5x+4.75y=77.5 plug 13-y in for x

6.5(13-y)+4.75y=77.5 distribute

84.5-6.5y+4.75=77.5 combine like terms

84.5-1.75y=77.5

-84.5          -84.5

-1.75y=-7 divide both sides by -1.75

*y=4* plug into x+y=13

x+4=13 subtract 4 from each side

*x=9*

a

step-by-step explanation:

the answer is a

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for