Explanation:
let the ginger ales be $x and the bagels $y.
Case 1, 2x+2y=6.60 x+y=3.30 ......1
Case 2, 4x+3y=11.70. .....2
1, x+y=3.30...×4
2, 4x+3y=11.70...×1
1, 4x+4y=13.20
2, 4x+3y=11.70
(-) (-) (-)
____________
y=1.50
____________
now, placing the value of y in equation 1,
x+y=3.30
x+1.50=3.30
x=1.80
therefore, the exact cost of one bagel and one ginger ale is $1.50 and $1.80 respectively.
hope this helps you.