Afair coin is tossed 5 times in a row. the exact probability of the coin landing heads exactly 2 times is?
in fractions

Zoe placed colored blocks on a scale in science class. each block weighed 0.8 ounces. the total weight of all the colored blocks was 12.8 ounces. how many blocks did zoe place on the scale? write and solve an equation to find the answer.

Aiden buys two bags of chips at $1.09 each and a 20 ounce soda for $1.20 at the gas station.he knows that the state tax is 5.5. how much change will he receive from a $5 bill?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?