A certain amount of coffee is mixed at 34 euros per kilo, with 80 kilos of another coffee at 50 euros per kilo, to obtain a mixture that can be sold at 44 euros per kilo. How much coffee of 34 euros should be used in the mixture?

The last answer choice

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.