Factor the expression. 40z – 20

Henry is an avid reader, he devours 90 pages in half an hour how many pages has henry read per minute?

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Aculture started with 4,000 bacteria. after 5 hours, it grew to 5,200 bacteria. predict how many bacteria will be present after 19 hours. round your answer to the nearest whole number.