The answer to make this statement true

Which of the following is the equation that says that the product of a number and ten is equal to 20 percent of that number ? a) 10n= 2.0n b) 10+n=.20n c) n+ .20n=10 d) 10n=0.20n

What is the area of a pizza with a radius of 40 cm leave the answer in terms of π to find your exact answer 40π cm² 1600π cm² 800π cm² 80π cm² π=pi

Me solve this problem, and someone clearly explain to me how to solve it.1.) use the value of the discriminant to determine if the given trinomials has 2 real solutions, 1 real solution, or no real solutions.a.  x2  − 4x  − 7 = 0b. 4r2  + 11r  − 3 = 0c. 3m2  + 7 = 0d.  t2  + 2t  + 1 = 0