Simplify. could i get an explanation too? . due soon

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

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