Question

Which is the equation in slope-intercept form of the line that contains points E and F?

A. 4x-y=12
B. y-4=4(x-4)
C. y=4x-12
D. x-4=4(y-4)

Answer 1

• F(3,-4)
• E(4,4)

Equation in two points form

`\\ \tt\longmapsto y+4=(4+4)/(4-3)(x-3)`

`\\ \tt\longmapsto y+4=8(x-3)`

`\\ \tt\longmapsto y+4=8x-24`

`\\ \tt\longmapsto 8x-y=28`

• Convert to y=mx+b form

`\\ \tt\longmapsto y=8x-28`

Answer 2

• C. y = 4x - 12

Explanation:

The coordinates of E and F are:

• E(4, 4) and F(2, -4)

Find the slope:

• m = (- 4 - 4)/(2 - 4) = - 8 / - 2 = 4

Use point-slope form and point E:

• y - 4 = 4(x - 4)

Convert into slope-intercept form:

• y = 4x - 16 + 4
• y = 4x - 12

The matching choice is C