Sam is 3 years younger than marco. marco is 15. how old is sam ? this is only 2 answer question

With this one. will mark brainliest

Adriana sold 50 shares of a company’s stock through a broker. the price per share on that day was $22.98. the broker charged her a 0.75% commission. what was adriana’s real return after deducting the broker’s commission? a. $8.62 b. $229.80 c. $1,140.38 d. $1,149.00

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2