Protons and neutrons are the most massive particles in the nucleus of an atom. If a nucleus were the size of an average grape, it would have a mass greater than 9 million metric tons. A
metric ton is 1000 kg. What would the mass of a grape-size nucleus be in kilograms? Write
your answer in scientific notation.

you need a common difference between consecutive terms to be constant, like 1,2,3,4 or 2,4,6,8, or 1,3,6,9

it's d.

step-by-step explanation:

because: -1(4x + 1y) +2 (1x-3y) distribute each number into the parenthesis.

then you would get: -4x - 1y + 2x -6y combine like terms

and get: 2x -7y

hope my answer has you if not then i'm sorry.

yes the total will be same because in both of them the expression.is rearranged but their sign remains the same hence it hss just been shuffled