Help me again pls :))

Olivia uses the work below to determine 55% of 720 which explains the error in olivia’s solution

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

The sum of the squares of two numbers is 8 . the product of the two numbers is 4. find the numbers.