Answer:
Question 2:
We need to find the value of x when the amount of money in both accounts is the same. This means that we need to set the two equations equal to each other and solve for x:
10x + 25 = 5x + 50
5x = 25
x = 5
Therefore, after 5 weeks, both siblings will have the same amount of money. The answer is 5 weeks.
Question 3:
The slope of a line passing through two points (x1, y1) and (x2, y2) is given by (y2 - y1) / (x2 - x1). Therefore, the slope of the line passing through (-3, -1) and (3, 8) is (8 - (-1)) / (3 - (-3)) = 9/6 = 3/2. The answer is three halves.
Question 4:
The total number of trials is 200, so the probability of getting no heads is equal to the frequency of getting tails twice, which is 35/200 = 0.175 or 17.5%. The answer is 17.5%.
Question 5:
A proportional relationship is one in which y varies directly with x, that is, y = kx where k is a constant of proportionality. The equation y = -2 is a horizontal line, which means that y does not vary with x and there is no proportional relationship. The equation y = 3x + 1 does not have a constant ratio of y to x, so it does not represent a proportional relationship. The equation y = (3/2)x and y = (1/2)x - 3 both have a constant ratio of y to x, so they represent proportional relationships. The answer is y equals three halves times x or y equals one half times x minus 3.
Question 6:
A fair, 6-sided die has four outcomes greater than 4, namely 5 and 6 on each of two rolls. The probability of getting a number greater than 4 on one roll is 2/6 = 1/3. Since the rolls are independent, the probability of getting a number greater than 4 on 45 rolls is the same as the probability of getting a head on 45 coin flips, which is approximately 0.5 x 45 = 22.5 or 23. The answer is 23.
Question 7:
To rotate a point (x, y) 90 degrees counterclockwise about the origin, we swap the x and y coordinates and negate the new x coordinate. Therefore, to rotate triangle UVW, we apply the same transformation to each of its vertices:
U' = (1, -1)
V' = (4, 0)
W' = (1, 4)
The answer is U′(1, −1), V′(4, 0), W′(1, 4).
Question 8:
The scatter plot shows a decreasing linear association. As the number of cupcakes increases, the cost per cupcake decreases. The slope of the line of best fit would be negative. The answer is there is a strong, negative linear association.
Question 9:
To rotate polygon ABCD to A′B′C′D′, we need to apply a counterclockwise rotation about the origin. To determine the angle of rotation, we can look at the change in coordinates of a point that is not the origin. For example, the point A moves from (-7, 5) to (5, 7), which is a translation of (12, 2).