Evaluate the expression 3.14(a2 (a squared) + ab) when a = 4 and b = 2. (input decimals only, such as 12.71, as the answer.)

First, start out by inserting the numbers: 

3.14(4(2) (4^2) + 4(2) 

Next, multiply the given numbers: 

3.14(8 (4^2) + 8) 

Then, multiply 4^2 (since the exponent is 2, multiply 4 two times: 4 * 4): 

3.14(8 (16) + 8) 

Now, multiply the first 8 to 16: 

3.14(128 + 8) 

Use the distributive property to solve this next one: 

401.92 + 25.12 

Finally, add up you two decimals: 

427.04 
You should get 427.04 (I could be wrong though). 
Hopefully that helped! :) 

Google it that might work