Question

Find the equation of the line that goes through (1,1) and has a slope of 2

Answer 1

`y = 2x - 1`

Explanation:

Slope-intercept form of equation of line:

`y = mx + c`

where:

m = slope

= 2

c = y-intercept

(which is determined by either reading directly from the graph or calculating it mathematically)

Mathematical Calculation of c:

Substitute the x- and y-coordinates of the given point in the above equation of line to solve for c:

`1 = (2)(1) + c`

`1 = 2 + c`

∴
`c = 1 - 2`

`= -1`

Substitute the values of m and c in the equation of line:

`y = (2)x + (-1)`

∴
`y = 2x -1`