I’m working on an homework assignment in accounting. Please help.

Key comparative figures ($ millions) for two companies, Alltech and SynergyXT, are presented in the following table.
Key Figures    Alltech    SynergyXT
Liab. + OE       $11,502    $48,823
Net income    3,127    9,276
Sales           15,453    44,612

What is the total amount of assets invested in each company?
Total assets = Liabilities + Equity
Alltech: $11,502 (is this correct?)
SynergyXT: $48,823 (is this correct?)

What is the return on assets for each company? Alltech’s beginning-year assets equal $8,101 (in millions) and SynergyXT’s beginning-year assets equal $36,171 (in millions).
Revenues – Expenses = Net income
Alltech: ($8,101 + $11,502)/2 = $9,801 Average Assets (in millions) (is this correct?)
SynergyXT: ($36,171 + $48,823)/2 = $42,497 Average Assets (in millions) ((is this correct?)?

How much are expenses for each company?
Revenues – Expenses = Net income
Alltech: $15,453 – Expenses = Net income (this is where i get stuck)
SynergyXT: $44,612 – Expenses = Net Income (this is where i get stuck?

Is return on assets satisfactory for each company? Assume competitors average an 18 percent return.

What can you conclude about Alltech and SynergyXT from these computations?