Sandy gave some marbles to her friend. She used the expression 9 + 15 x 2-31 to find out how many marbles she had left. How many marbles did she have left?

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

Compare the following pair of numbers a and b in three ways. a. find the ratio of a to b. b. find the ratio of b to a. c. complete the sentence: a is percent of b. a=120 and b=340 a. the ratio of a to b is . b. the ratio of b to a is . c. a is nothing percent of b.

Which shows how to solve the equation 3/4x=6 for x in one step?