one way is to just multply them out but the easier way is to undistribute to see the answer
so
remember distributive property
a(b+c)=ab+ac
4a+10 is obvously a product
the common factor is 2 so
4a+10=2(2a)+2(5)
undistribute 2
2(2a)+2(5)=2(2a+5)
reverse distribute
answer is last option
