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URGENT PLEASE HELP!!Which is an equation of the line that has a slope of 2 and passes through the point (3,1)?

A. y=2r +5
B. y = 2x + 1
C. y = 2x - 1
D. y = 2x - 5

User Mzy
by
4.9k points

1 Answer

5 votes

Answer:

The equation of the line is y = 2x - 5 ⇒ D

Explanation:

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

  • m is the slope
  • b is the y-intercept

Note: To prove that a line passes through a given point, substitute x in the equation of the line by the x-coordinate of the point and solve to find y, if y equals the y-coordinate of the point, then the line passes through it

∵ The slope of the line is 2

∵ The line passes through the point (3, 1)

→ Find at first which equation has slope 2, then check if the line passes

through the point or not using the note above

A.

y = 2x + 5

→ By comparing it with the form of the equation above

∴ m = 2

The line has the same slope

→ Substitute x by 3 to find y

∵ y = 2(3) + 5 = 6 + 5 = 11

∵ y-coordinate of the point = 1

The line does not pass through the point

B.

y = 2x + 1

→ By comparing it with the form of the equation above

∴ m = 2

The line has the same slope

→ Substitute x by 3 to find y

∵ y = 2(3) + 1 = 6 + 1 = 7

∵ y-coordinate of the point = 1

The line does not pass through the point

C.

y = 2x - 1

→ By comparing it with the form of the equation above

∴ m = 2

The line has the same slope

→ Substitute x by 3 to find y

∵ y = 2(3) - 1 = 6 - 1 = 5

∵ y-coordinate of the point = 1

The line does not pass through the point

D.

y = 2x - 5

→ By comparing it with the form of the equation above

∴ m = 2

The line has the same slope

→ Substitute x by 3 to find y

∵ y = 2(3) - 5 = 6 - 5 = 1

∵ y-coordinate of the point = 1

The line passes through the point

The equation of the line is y = 2x - 5

User Kevin Pang
by
4.6k points