12/5 & 12/6 DCP #2 Review

Front

What does it mean for y to vary directly as x?

Back

It means that as x increases, y increases proportionally. This can be expressed as y = kx, where k is a constant.

Front

If x = 27 when y = 6, what is the constant of variation (k)?

Back

k = y/x = 6/27 = 2/9.

Front

How do you find the value of x when y = 2 in a direct variation problem?

Back

Use the formula y = kx. Substitute y = 2 and k = 2/9 to find x.

Front

What is the formula to calculate the slope (m) between two points (x1, y1) and (x2, y2)?

Back

m = (y2 - y1) / (x2 - x1).

Front

Calculate the slope between the points (-3, 3) and (7, 6).

Back

m = (6 - 3) / (7 - (-3)) = 3 / 10.

Front

What does a weak negative correlation indicate about two variables?

Back

It indicates that as one variable increases, the other variable tends to decrease, but the relationship is not strong.

Front

What is the slope of a line that is parallel to y = 5x - 3?

Back

The slope is 5, since parallel lines have the same slope.

Front

How do you write the equation of a line in slope-intercept form?

Back

The equation is written as y = mx + b, where m is the slope and b is the y-intercept.

Front

If the number of apples sold varies directly as the cost, what is the formula to find the cost?

Back

Cost = k * number of apples, where k is the cost per apple.

Front

If 4 apples cost $0.45, what is the cost of 1 apple?

Back

Cost per apple = $0.45 / 4 = $0.1125.