Answer:
(13+9)+4=26
explaiation
the order of numbers in an addition problems doesn't affect the Sum
She is wrong. The way we know this is by this. If you are going 70 mph for 30 miles than you have to spilt the mph sign in half so 35 miles in 30 minutes.The you subtract 4 from each getting 31 miles in 26 minuets. Therefore Lethna is wrong.
Solve the multiplication first then the division and the subtract them to get something like this:

which simplifies to 29.7 (3 significant figure )