Question

In math class, students must randomly draw a card that contains an equation that they must graph on the board.

If the cards contain the following equations, what is the probability that a student will graph a line whose slope is 3?

3y = 9x + 3
x(x + 3) = 0
3x + y = 0
x = 3y
x 2 + 3 = 0
y - 3x = 0

Answer choices: (1/6, 1/3, 1/2, 2/3)

Answer 1

Answer: b

Explanation:

Answer 2

2/3

Explanation:

How many equations here have a slope of 3?

We need to find them and count them.

3y = 9x + 3

1st. y = 3x + 1 has slope 3

2nd ... x(x+3) = 0 is not a line

3rd. 3x + y = 0 y = -3x

4rth. x^2 + 3 = 0 is not a straight line

5th y - 3x = 0 is y = 3x yes has slope 3

Only 2 equations have a slope of 3. 2 out of 5 total but...

But there are only 3 equations here that are straight lines

so 2 out of 3