A local kids play sold 8 adult tickets and 9 child tickets for a total of $205. On day two they sold only 4 adult tickets and 3 child tickets for a total of $83. What was the price of each kind of ticket?

Adult tickets cost $11 and child tickets cost $13

Step-by-step explanation:

Multiply the second equation by -2, then add the equations together.

(8a+9c=205)

−2(4a+3c=83)

Becomes:

8a+9c=205

−8a−6c=−166

Add these equations to eliminate a:

3c = 39

Then solve3c=39for c:

3c=39

=

(Divide both sides by 3)

c = 13

Now that we've found c let's plug it back in to solve for a.

Write down an original equation:

8a+9c=205

Substitute 13 for c in 8a+9c=205:

8a+(9)(13)=205

8a+117=205 (Simplify both sides of the equation)

8a+117+−117=205+−117 (Add -117 to both sides)

8a=88

=

(Divide both sides by 8)

a = 11

answer is c

step-by-step explanation:

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