Question

A line has a gradient of 4 and passes through the post (1,7). what is the equation?

Answer 1

y = 4x + 3

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = 4, thus

y = 4x + c ← is the partial equation

To find c substitute (1, 7) into the partial equation

7 = 4 + c ⇒ c = 7 - 4 = 3

y = 4x + 3 ← equation of line

Answer 2

The equation is y = 4x+3

Explanation:

The slope intercept form of a line is

y = mx+b where m is the slope and b is the y intercept

y = 4x + b

Substitute the x and y value into the equation

7 = 4(1)+b

7 = 4+b

Subtract 4

7-4 =b

3=b

The equation is y = 4x+3