If the diameter of a wheel os 0.5meters, then the radius of the wheel is how many centimeters?

Pls me this is due today and i need i will make brainliest if you me answer correctly and i will report if you try to give me a dumb answer.

When x = 3 and y = 5, by how much does the value of 3x2 – 2y exceed the value of 2x2 – 3y ?

Can someone me with my math problems i have a bunch. i will give brainliest and lots of pleeeaaasssee