Help Help Is easy just tell me if my answer is right or not and maybe tell me why?

Answer asap ill give ! ’ a sample of radioactive material decays over time. the number of grams, y , of the material remaining x days after the sample is discovered is given by the equation y = 10(0.5)^x. what does the number 10 represents in the equation? a. the half-life of the radioactive material, in days b. the amount of the sample, in grams, that decays each day c. the time, in days, it will take for the samples to decay completely d. the size of the sample, in grams, at the time the material was discovered

Susie wants to take her friend out for lunch.she wants to spend $9.75 each person. how much will she spend in all.

One of the solutions to x2 - 2x – 15 = 0 is x = -3. what is the other solution? ox=-5 ox= -1 0 x=1 x = 5