Given f (x) = 3x+9 find x when f (x) = 21

Linda is putting money into a savings account. She starts with $450 in the savings account, and each week she adds $70.

Explain how precise and significant digits are important

Order from least to greatest 4.5 3.9 4.258 3.75 4.256

53 degrees below zero

G more than 85 is 339

Eight hundred thousand, six hundred twenty four in number form

Marcy bought 10.32 pounds of white potatoes and 12.48 pounds of sweet potatoes. About how many pounds of potatoes did Marcy buy? Round each weight to the nearest tenth to estimate the total weight of potatoes that Marcy bought.

Let X = {5, 10, 15, 20, 25, 30, 35, 40}. Define a relation on X as follows. For a, b is in X, a b if b can be obtained from a by adding a (possibly empty) collection of dimes (10 cents) and quarters (25 cents). So, for example, 25 35, but 25 30.

Lindell ran 5 kilometers in 25 minutes. How fast did he run in miles per hour?

If f (x) = x^2+9x and g (x) = 1/x, find f (g (-1)).