Which method is the most efficient method to use to solve 2x^2+4x-3=0?

What is the celsius temperature that is equal to 94 degrees fahrenheit using the formula f=9/5 c+32

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

Janet is rolling a number cube with the numbers one through six she record the numbers after each row if she rolls of keep 48 times how many times should she expect to roll a 4