Rudy writes the sample work below.

18 = 2x + 6

18 + (–6) = 2x + 6 + (–6)

which property did rudy use?

a: addition property of equality
b: transitive property of equality
c: reflexive property of equality
d; multiplication property of equality

Marco is studying a type of mold that grows at a fast rate. he created the function f(x) = 345(1.30)x to model the number of mold spores per week. what does the 1.30 represent? how many mold spores are there after 4 weeks? round your answer to the nearest whole number. 1.30 represents the number of mold spores marco had at the beginning of the study; 985 mold spores 1.30 represents the number of mold spores grown in a given week; 448 mold spores 1.30 represents the 30% rate of weekly growth; 345 mold spores 1.30 represents the 30% rate of weekly growth; 985 mold spores

Fatima plans to spend at least $15 and at most $20 dollars on sketch pads and pencils. if she buys 2 sketchpads, how many pemcils can she buy while staying in her price range? fatima can buy between and pencils. ? (type whole numbers. use ascending? order.)

Ithink i know it but i want to be sure so can you me out ?