Find the value of
81^-1/2

The marked price of an article is 25% above its selling price and the cost price is 30% less than its marked price . find the discount percent and gain percent. only a brainlest can solve it i will mark you brainlest

Pls as soon as ! will award brainliest and 20 ! also the answer is not 22.5 degrees! find the value of x in each case:

How many and of which kind of roots does the equation f(x)=x3−x2−x+1