Question

Tu went to the movies. He bought 2 tickets for $9.50 each, popcorn for $5.00 and 2 drinks for $4.25 each. He gave the clerk two $20.00 bills. Which expression can NOT be used to find the amount of change Tu got?

A $40.00-$9.50-$4.25-$5.00
B $40.00 - $9.50 - $9.50 - $5.00 - $4.25 -$4.25
C $40.00 - (2x $9.50) - (2 x $4.25) - $5.00
D (2 x $20.00) - (2 x $9.50) - (2 x $4.25) - $5.00

Answer 1

A

Explanation:

A is the only equation that does not account for the fact that Tu bought 2 tickets and 2 drinks.

The rest do: B subtracts the appropriate amounts twice, C multiplies the doubled expenses, and D does the same, just the amount paid is also separated.

Answer 2

A

Explanation:

The total bill is

2 tickets = 2* 9.50 = 19

1 popcorn = 5

2 drinks = 2* 4.25 = 8.50

The total bill is

He wants change from a 40

40 - (2*9.50 +5+2*4.25) This is C

Distributing the minus sign

40 - (2*9.50) -5-(2*4.25)

Leaving the 40 as 2 twenties

2*20- (2*9.50) -5-(2*4.25) This is D

Separating the multiplication into addition

40 - 9.50 -9.5 -5 - 4.25 -4.25 This is B

We cannot use A because it is only 1 ticket and 1 drink