I usually do 10 points but now I am doing 12 and making someone who answers all questions correctly brainlist for sure promised plz and thx can anyone help me don't delete my question plz i need help on my new lesson we got today send them overmy num 407632170 or snap rockymunta

the answer is 510

step-by-step explanation:

15 • 13 = 195

15 • 12 = 180

15 • 5 = 75

12 • 5 = 60

195 + 180 = 375

375 + 75 = 450

450 + 60 = 510

21

step-by-step explanation:

chemists are often responsible for designing a chemical reaction and analyzing the products obtained from it. one significant part of designing a chemical reaction is determining the amount of each reactant that is needed and the amount of each product that will be produced. in order to do so, chemists use stoichiometry, the quantitative relationships between reactants and products.