The correct answer is 370. A system of equations can be
used, where h represents the number
of calories in a hamburger and f represents
the number of calories in an order of fries. The equation 2 h plus 3 f equals 1,700 represents the
fact that 2 hamburgers and 3 orders of fries contain a total of 1700 calories,
and the equation h equals f
plus 50 represents the fact that one hamburger contains 50 more
calories than an order of fries. Substituting f plus 50 for h in
2 h plus 3 f equals 1,700 gives 2, parenthesis, f plus
50, close parenthesis, plus 3 f, equals 1,700. This equation
can be solved as follows:
2 f plus 100 plus 3 f equals 1,700
5 f plus 100 equals 1,700
5 f equals 1,600
f equals 320
The
number of calories in an order of fries is 320, so the number of calories in a
hamburger is 50 more than 320, or 370.