Math was my major in college and Fansico's answer is the most precise and correct, except for one thing:
six pint five times open parenthesis four point eight minus THE PRODUCT OF one point two times four close parenthesis
At least that is how I would tell it to another math student.
If I didn't know much math, but wanted to give a clear description, I might say this:
Multipy 1 point 2 times 4
Subtract the result from 4 point 8
Multiply that result times 6 point 5
Following either of these sets of directions should give you the desired result.