Paleontologist have put together bones to make a t-rex skull that has a mass of 600 pounds. they just found a new tooth fossil to add to the skull that has a mass of 40 ounces. how many pounds is the t-rex skull with the new tooth?

In trapezoid efgh, m∠hef=(4x2+16)∘ and m∠gfe=(5x2+12)∘. find the value of x so that efgh is isosceles. i'm desperate.

Rachel reads 1/5 of the pages of a book plus 12 pages on the first day. on the second day, she reads 1/4 of the remaining pages plus 15 pages. on the third day, she reads 1/3 of the remaining pages plus 18 pages. on the fourth day, she reads the remaining 70 pages. how many total pages are in the book?

Which of the following answers is 5/25 simplified? 1/5 5/5 2/5 1/25