I still don't understand can someone help me?

the everton college store paid $1553
for an order of 42 calculators. the
store paid $9 for each scientific calculator. the others, all graphing calculators, cost the store $56 each. how many of each trupe of calculator was ordered?

the store ordered:
how many scientfic calculators?

graphing calculators?

2 answers

how about...

let the number of scientific calculators be x
then the number of graphing calc's is 42-x

then 9x + 56(42-x) = 1553
9x + 2352 - 56x = 1553
-47x = -799
x = 17
42-x = 25

So they bought 17 scientific and 25 graphing types.

check : 17(9) + 25(56) = 1553
Reiny is mostly correct how I think about it is I think about what I know write it down I see what they are asking me and try to figure it out. Try to make it easier for you to understand