Assign variables to you unknowns.
c = $ cars
t = $ trucks
6c + 3t = 4800
8c + t = 4600
use substitution or elimination to solve the system of equations.
using elimination.. multiply second equation by -3 and add to the other to combine equations into one.
6c + 3t = 4800
-3(8c + t = 4600)
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-18c + 0 = -9000
c = 9000/18
c = 500 $
use this in one of the equations to find the cost of a truck.
8(500) + t = 4600
4000 + t = 4600
t = 4600 - 4000
t = 600 $
question asks
2(500) + 3(600) =
1000 + 1800 = 2800 $
It's simple you've been told that correct answers equals 6/7 and she did all the questions. Therefore the incorrect answers equals 1/7, which is 4. So just times 4 by 7. 4 x 7 = 28. 28 questions on the quiz.
The answer would be 54, because A= PQ over 2 = 9 x 12 over 2 = 54
