Evaluate : fc3y) if f(x) = x² +3

Identify an equation in point slope form for the line perpendicular to y=3x+5 that passes through (4,-1)

Mat bought a phone for $100. he has to pay $30 per mouth. if he has paid $640 in total, how many mouth has he had the phone?

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms