<h3>1.</h3>
The equation in point-slope form: y - y₁ = m(x - x₁)
slope: m = -2
point: (4, -5) ⇒ x₁ = 4, y₁ = -5
Therefore, the equation of the line in point-slope form:
<h3>
y + 5 = -2(x - 4)</h3>
<h3>2.</h3>
The equation in slope-intercept form: y = mx + b
Parallel lines has the same slope, so:
y = 4x + 2 ⇒ a = 4
If a line passes through the point <em>(x₁, y₁) </em>then the equation y<em>₁</em> = mx<em>₁</em> + b is true.
(4, 6) ⇒ x₁ = 4, y₁ = 6
So: 6 = 4·4 + b ⇒ b = -10
Therefore the equation:
<h3>
y = 4x - 10</h3>
<h3>3.</h3>
a = 3
(-1, 1) ⇒ x₁ = -1, y₁ = 1
So: 1 = 3·(-1) + b ⇒ b = 4
The equation:
<h3>
y = 3x + 4</h3>
<h3>4. </h3>
The product of slopes of perpendicular lines is -1.
2x - 7y = 1 ⇒ 7y = -2x + 1 ⇒ y = -²/₇x + ¹/₇
-²/₇×m = -1 ⇒ m = ⁷/₂
(0, -4) ⇒ x₁ = 0, y₁ = -4
-4 = ⁷/₂·0 + b ⇒ b = -4
The equation:
<h3>
y = ⁷/₂x - 4</h3>
