Question

Write an equation of the line, in slope-intercept form, that passes through (-2, 5) and (1, -1).

Answer 1

y = -2x + 1

Explanation:

Formulae:

Slope:
`m=(y_2-y_1)/(x_2-x_1)\\`

• m = slope
• y₂ = second y-value
• y₁ = first y-value
• x₂ = second x-value
• x₁ = first x-value

Point-slope form:
`y-y_1=m(x-x_1)`

• y₁ = first y-value
• m = slope
• x₁ = first x-value

Slope-intercept form:
`y=mx+b`

• m = slope
• b = y-intercept value

Calculations:

`m=(-1-5)/(1-(-2))\\m=(-6)/(3)\\m=-2`

`y-5=-2(x-(-2))\\y-5=-2(x+2)\\y-5=-2x-4\\y=-2x+1`