Which multiplication equations below can be used to help solve 480 ÷ 8? A. 8 × 50 = 400; 8 × 10 = 80 B. 4 × 100 = 400; 4 × 20 = 80 C. 2 × 200 = 400; 2 × 40 = 80 D. 10 × 40 = 400; 10 × 8 = 80

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

Yahir designs bracelets. he uses between 9 and 15 red and yellow beads in the ratio of 2 red bead to 5 yellow beads. drag the beads into the container to meet these requirements

What number is 7 units left of -15?