Which equation can be used to solve for the unknown number? Seven less than a number is thirteen.
n minus 7 = 13
7 minus n = 13
n + 7 = 13
n + 13 = 7

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.

How many times larger is 9 × 10^8 than 3 × 10^-5? a. 3 × 10^13 b. 3 × 10^-40 c. 3 × 10^-13 d. 3 × 10^3

Can you make 1000, using only eight 8’s? if you had your choice, would you rather have 5 million dollars, or 1 penny, doubled every day for a month?