Need asap- five questions on scientific notation

combine the like terms in the expression.

a. -12x^4 + 7x^4 + 6x^4

b. 2r + 7r + 16x

c. 30z^8 + 7z^8 + 8z

d. 15a^2 - 15b^2 + 13a^2 - b^2

e. 7x^2 - 82x + 12x^2 - 2x

An equation representing lyle’s hedge-trimming business is a = 12n - 300 where a is the amount of profit or loss in dollars and n is the number of hedges trimmed. how would the graph of lyle’s business change if the equation a = 10n - 300 represented his business? the graph would be flatter. the graph would be steeper. the graph would start closer to the origin. the graph would start lower on the y-axis.

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5

What are the coordinates of the point that is 1/3 of the way from a to b? a (2,-3) b (2,6)