15. Simplify (10)(-5)-1). C. 13 B. - 10 A. -16 D. 60 16. What integer multiplied by 5 gives a product of -20? B. - 2 A.- 4 D. 5 C. 3 9(4) - 8 17. Simplify -2-2 A - 7 B. - 5 D. 7 C. 5 18. A box of face mask that contains 50 pieces costs 125 pesos. If Myrna wants to sell 10 pesos per piece, how much is her profit per box? A. 175 pesos C. 500 pesos B. 375 pesos D. 6,250 pesos 19. Alvin bought a share of stocks for 2,435 pesos. The next day, the price dropped by 24 pesos. On the 3rd day, the price rose by 31 pesos. How much was Alvin's stock worth at the end of the 3rd day? A. 2,442 pesos C. 2,424 pesos B. 2,490 pesos D. 2,380 pesos 20. A boy walks 6 blocks north, another 2 blocks north, then decides to go back 4 blocks south. Where is he now? A. 2 blocks north C. 8 blocks south B. 4 blocks north D. 10 blocks south

I'm already get in highschool right and I can't understand this one pls help be nice ask ​