HELP WITH RATIONAL OR IRRATIONAL NUMBERS!! EXPLAIN AND I WILL NOT OPEN LINKS SO DONT WASTE YOUR TIME

How do i do this activity, is appreciated

Me! last question, and i'm stuck! write the algebraic expression that models the word phrase. the product of 2 divided by the number h and 8 more than the number k

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.