Tania went grocery shopping and bought 8 apples at a cents each and 10 bananas at b cents each. she claims she spent a total of 18ab on groceries. is she
correct? explain your answer as clearly as possible

Tania is NOT correct~

The amount of money she spent on apples is: 8a (cents)
The amount of money she spent on bananas is: 10b (cents)

The total amount of money she spent on apples and bananas is:
8a+ 10b (cents)

8a+ 10b 
= 2(4a+ 5b) (distributive property)

Because 2(4a+ 5b) ≠ 18ab, she is not correct.

Hope this helps~

When i did the math i got 11 cm

Definitely