You bought 5 chocolate bars and 8 blow pops for $23.25. Your sister bought 2 chocolate bars and 13 blow pops for $21.55. How much did each chocolate bar cost? Each chocolate bar cost?

Cost of each chocolate bar  = $2.65

Cost of each blow pop  = $1.25

Step-by-step explanation:

Let x = Cost of chocolate bar

y= Cost of blow pops

We can make system of equations and find value of x and y

You bought 5 chocolate bars and 8 blow pops for $23.25.

Your sister bought 2 chocolate bars and 13 blow pops for $21.55.

Let:

Multiply eq(1) with 2 and eq(2) with 5 and subtract

So, value of y = 1.25

Putting value of y in eq(1) to find value of x

Value of x = 2.65

So, Cost of each chocolate bar = x = $2.65

Cost of each blow pop = y = $1.25

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

what level of math? also i don't need to be paid if i can you.