18(4x + 8) Please simplify, I really don't want to get it wrong.

Hiroki wrote a number that is the opposite of -3. what number did hiroki write? a. ⅓ b. 3 c. 0 d. -3

In simplified exponential notation, the expression a^2•a^-3•a 1/a 0

Gregory draws a scale drawing of his room. the scale that he uses is 1 cm : 4 ft. on his drawing, the room is 3 centimeters long. which equation can be used to find the actual length of gregory's room?