How tall is the tallest man alive

Find the nonpermissible replacement for binthis expression.b2/5b +5

Prove that (x-2)is factor of p (x)=2x³-3x²-17x+30

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)