Please help spent a lot of time on this

Which ordered pair (c, d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

Scott’s bank account showed a balance of $750 on sunday. during the next five days, he made one deposit of $140 and numerous withdrawals of $180 each. let x represent the number of withdrawals that scott made. write an inequality that can be used to find the maximum number of withdrawals that scott could have made and maintain a balance of at least $100. do not use a dollar sign ($) in your response.

How many times larger is 6 × 10^12 than 2 × 10^7? a. 30,000 b. 3,000 c. 3,000,000 d. 300,000