Thursday, December 10, 2009

Math question.?

"A movie theatre charges $7.50 for adults and $4.50 for children. The receipts for one showing of a movie were $540. If 80 tickets were sold, find how many tickets of each type were sold."



I'm just checking my answers here... do you know the answer? Please show me how you got to your answer. :)



Math question.?violin



adult tickets, variable = 'a'



child tickets, variable = 'c'



You know two things: the total amount sold



$7.50 a + $4.50 c = $540



and the total number of tickets



a + c = 80



Solve the second equation for one of the variables. Let's do a, so a = 80 - c



plug a = 80 - c back into the first equation,



7.5 (80 - c) + 4.5 c = 540



(7.5 x 80) - 7.5 c + 4.5 c = 540



600 - 3 c = 540



600 - 540 = 3c (subtracted 540 and 3c from each side)



3c = 60



c = 20 (20 children's tickets)



plug c back into the second equation to find out how many adult tickets



a + c = 80



a = 80 - c



a = 80 - 20



a = 60 (60 adult tickets)



Double check, does 60 x 7.5 and 20 x 4.5 add up to 540?



450 + 90 = 540



Yee Haw. 60 adult tickets and 20 child tickets.



(If you need to solve for two variables, you need to have two equations. Solve for one variable using the first equation, then plug the result of that back into the second and you have your solution.)



Math question.?chinese theater opera theater



You have 2 equations from the word problem:



7.50x + 4.50y = 540



x + y = 80



Isolate x:



x = 80 - y



Sub in x value for first equation:



7.5(80-y) + 4.50y = 540



600 - 7.5y + 4.5y = 540



-3y = -60



y = 20



Sub y back into 2nd equation to get x:



x + 20 = 80



x = 60



Now you have the answer:



20 children, 60 adult
7.5 * X + 4.50 * (80 - x) = 540



7.5X + 360 - 4.5X = 540



3X = 180



X = 60



80 - (60) = 20



So they bought 60 adult tickets at $7.50 and 20 child tickets at $4.50
7.5 * X + 4.50 * (80 - x) = 540



7.5X + 360 - 4.5X = 540



3X = 180



X = 60



80 - (60) = 20



simple
X+Y=80



7.5X+4.5Y=540



if X+Y=80 then Y=-X+80



Plug in the equation for Y



7.5X+4.5(-X+80)=540



Distibute 4.5



7.5X-4.5X+360=540



Subtract 360 and combine the variables.



3X=180



Divide by 3



X=60



Plug X into the first equation



X+Y=80



60+Y=80



Subtract 60



Y=20



So, your final answer is that 60 adult ticks and 20 children's tickets were sold

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