Answer:
Step-by-step explanation:
Collecting terms, you get ...
... = xy²(5 1/2 -2 2/5 -1 3/5 -1/2) = xy²((5 1/2 -1/2) -(2 2/5 +1 3/5))
... = xy²(5 - 4) = xy²
Substituting the give values for the variables and doing the arithmetic, you get ...
... xy² = 3.9×4² = 3.9×16 = 62.4
