Need the last one is the question and the first one is. number 20 and the second is number worry about number 19 i already did thay as u can

Aresearch company wants to test the claim that a new multivitamin to improve short term memory. state the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure.

Simply 8x squared + 5(7x squared- x) - 2x =

What expression is equivalent to 42x-56y