Strontium 90 is a radioactive material that decays according to the function upper a left parenthesis t right parenthesis equals upper a 0 e superscript negative 0.0244 t baseline comma where upper a 0 is the initial amount present and a is the amount present at time t (in years). assume that a scientist has a sample of 400 grams of strontium 90. (a) what is the decay rate of strontium 90? (b) how much strontium 90 is left after 10 years? (c) when will only 300 grams of strontium 90 be left? (d) what is the half-life of strontium 90?

As part of an annual fundraiser to raise money for diabetes research, diane joined a bikeathon. the track she biked on was 1,920 yards long. diane biked 38.5 laps. her sponsors agreed to donate an amount of money for each mile she biked. how many miles did she bike? first fill in the blanks on the left side using the ratios shown. then write your answer. given ratios: 5280ft / 1 mi , 1 mi /5280 ft , 1,920 yards / 1 lap , 1 lap / 1,920 yards , 3 ft / 1 yard , 1 yard / 3 ft. blanks: 38.5 laps / 1 yard x (blank) x (blank) x (blank) = (blank) miles i'm really confused on how to do this, and the explanations aren't exactly . if you could walk me through how to do this, it would be greatly appreciated.

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.

The answer is 7.2 how would you put this as money