Please answer, I'm doing a test and it is almost done!!! What is the value of the expression, written in standard form?

For the given quadratic equation convert into vertex form, find the vertex and find the value for x=6 y=-2x^2+2x+2

Daniel bought a computer game for $25 and later sold it to thomas for a 40% profit. how much did daniel sell the computer game for?

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?