Tramserran? do you think you could lend a hand for these questions? you have saved my life on more than one occasion. it's algebra, and would be appreciated.

1: 4 if the wew 35 surfboards at the beach how many were short boards?

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

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