Andrew M. answered 05/05/16
Tutor
New to Wyzant
Mathematics - Algebra a Specialty / F.I.T. Grad - B.S. w/Honors
Let x = # $24 hats
Let y = # $12 hats
we bought 18 hats so:
x+y=18 ... equation 1
the money spent will be
24x + 12y
we spent $336 so:
24x + 12y = 336 ... equation 2
note that each term in equation 2 is
divisible by 12 so we can reduce it.
12(2x + y) = 12(28)
2x + y = 28 ... equation 2
we have 2 equations and 2 unknowns
x + y = 18 equation 1
2x + y = 28 equation 2
--------------- subtract equation 1 from equation 2
x = 10
x+ y = 18
10+y=18
y= 8
He bought 10 of the $24 hats
and 8 of the $12 hats
check answer:
24(10) + 8(12) = 336
240 + 96 = 336
336 = 336
equation balances, answer is correct.