answer:To solve this problem, we need to determine the value of x, which represents the number of tumblers Mrs. Petersons bought. We know that each tumbler costs 45 and Mrs. Petersons paid with five 100 bills. The total cost of the tumblers is equal to the number of tumblers multiplied by the cost per tumbler: x * 45. The total amount Mrs. Petersons paid is equal to the number of bills multiplied by the value of each bill: 5 * 100. The change Mrs. Petersons will receive is equal to the total amount paid minus the total cost: 5 * 100 - x * 45. We can set up the equation as follows: 5 * 100 - x * 45 = 50 Let's simplify and solve for x: 500 - 45x = 50 To isolate x, we subtract 500 from both sides of the equation: 500 - 500 - 45x = 50 - 500 -45x = -450 Finally, we divide both sides of the equation by -45 to solve for x: x = -450 / -45 x = 10 The value of x is 10. 10 The answer is: 10

answer:For the first 40 hours, Janice earns 10 per hour, so she earns 40 * 10 = 400. She works 60 hours in total, so she works 60 - 40 = 20 overtime hours. For the overtime hours, she earns 15 per hour, so she earns 20 * 15 = 300. Therefore, Janice will earn a total of 400 + 300 = 700. 700 The answer is: 700

answer:The perimeter of the square lake is 4 x 15 = 60 miles. If it takes John 20 minutes to swim 1 mile, it will take him 20 x 60 = 1200 minutes to swim around the lake. Since there are 60 minutes in an hour, it will take him 1200 / 60 = 20 hours to swim around the lake. If John can row at twice the speed he can swim, it will take him half the time to row around the lake compared to swimming. So, it will take him 20 / 2 = 10 hours to row around the lake. 10 The answer is: 10

answer:We can rewrite the equation as x^2 + 4x = 0. Factoring out an x, we have x(x+4)=0. So, the solutions are x=0 and x=-4. Since we are looking for nonnegative solutions, the only solution is x=0. Therefore, the number of nonnegative solutions is boxed{1}.The answer is: 1