How do i round 218,457 to the hundred thousands

Y=4x^2+x-1 solve using quadratic formula

5× 1/2 = ? a) more than 5 because you are multiplying by a whole number b) 5/10 because you multiply the numerator and denominator by 5 c) less than 5 because you are multiplying by a number that is more than 1 d) less than 5 because you are multiplying by a number that is less than 1

What is the 12th term of b(n)=-4-2(n-1)