Can someone explain to me how to do this

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Daniel expanded the expression as shown below -2(-8x-4y+3/4)=-10x-8y-11/4 what errors did he make? check all that apply

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms