What's the equation of a line that passes through points (–1, –5) and (1, 3)?
2 answers:
Answer:
y = 4x - 1
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m =
with (x₁, y₁ ) = (- 1, - 5) and (x₂, y₂ ) = (1, 3)
m = =
= 4 , then
y = 4x + c ← is the partial equation
To find c substitute either of the 2 points into the partial equation
Using (1, 3 ) , then
3 = 4 + c ⇒ c = 3 - 4 = - 1
y = 4x - 1 ← equation of line
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1) Find the graph of a line passing through (-1, 4) and (2, 0).
The slope of two points can be determined by dividing the difference of y-values by the difference of x-values:
The slope of this equation is -4/3. Inputting this into the slope-intercept form of an equation, we get:
To find b, substitute x and y for one of the given coordinate pairs:
0 = (-4/3)(2) + b
0 = -8/3 + b
8/3 = b
Substitute the b value into the equation to finish the line:
Answer:
The mean of the combined group is 76.67 ≈ 77
Step-by-step explanation:
- The sum of the grades in Tom's group is 20×70 = 1400
- The sum of grades in Alice's group is 10×90=900
- The sum of gradees in the combined group is =1400+900=2300
- Then the mean grade of the combined group is
where
- 2300 is the sum of the all grades in the combined group
- 30 is the total number of people in the group