Let x = cost of soft drink
y = cost of sandwich
Equation: x + y = 56
But y = x + 8..since sandwich cost 8 more than the soft drink..
Substitute y to the equation:
x + (x + 8) = 56
2x + 8 = 56
2x = 56- 8
2x = 48
x = 48/2
x = 24 ...........COST OF SOFT DRINK
substitute the value of x to y = x + 8:
y = x + 8
= 24 + 8
y = 32 COST OF SANDWICH...ANSWER