Question

A. When x = -1, what is the value of y?

Answer 1

Answer:

a. When x = -1, the value of y = 3

b. When y = 7, the value of x = 1

c. The y-intercept is (0, 5)

d. The x-intercept is (-2.5, 0)

e. The slope of the line is 2

f. The equation of the line is y = 2x + 5

Step-by-step explanation:

The form of the linear equation is y = m x + b, where

• m is the slope

• b is the y-intercept (value y at x = 0)

The x-intercept is the value of x at y = 0

From the given graph:

a.

∵ x = -1

→ Look at the graph and find the y-coordinate of the point on

   the line whoes x-coordinate = -1

∴ y = 3

∴ When x = -1, the value of y = 3

b.

∵ y = 7

→ Look at the graph and find the x-coordinate of the point on

   the line whose y-coordinate = 7

∴ x = 1

∴ When y = 7, the value of x = 1

c.

∵ The y-intercept of the graph is the point of intersection of

   the graph and the y-axis

→ Look at the graph and find the y-coordinate of the point on

   the line whose x-coordinate = 0

∴ y = 5

∴ The y-intercept is (0, 5)

d.

∵ The x-intercept of the graph is the point of intersection of

   the graph and the x-axis

→ Look at the graph and find the x-coordinate of the point on

   the line whose y-coordinate = 0

∴ x = -2.5

∴ The x-intercept is (-2.5, 0)

e.

∵ The slope of the line m = Δy/Δx

→ Use the intercepts to find it

∵ The intercepts are (-2.5, 0) and (0, 5)

∴ Δx = 0 - (-2.5) = 2.5

∴ Δy = 5 - 0 = 5

∴ m = 5/2.5 = 2

∴ The slope of the line is 2

f.

∵ The form of the equation of the line is y = m x + b

∵ m = 2

∵ b = 5

∴ y = 2x + 5

∴ The equation of the line is y = 2x + 5