Simplify the expression. 7x² + 3 - 5(x² - 4)

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

80 points suppose marcy made 45 posts online. if 23 of them contained an image, what percent of her posts had images? round your answer to the nearest whole percent. 54 percent 51 percent 49 percent 48 percent

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?