using the points (3,1) and (1,-3) write an equation in slope-intercept form
i keep coming up with y=2x+6 but the back of my math book says its y=2x+5....am i wrong or is the book wrong? if im wrong plz show me the steps so i can compare them to my work
Your slope is correct at m=2
so your equation must be
y = 2x + b
sub in one of the points, say (3,1)
1 = 2(3) + b
b = -5
correct equation: y = 2x - 5
Both of the given points satisfy my equation, so you are both wrong.
thx u so much ^^
To write an equation in slope-intercept form, y = mx + b, where m represents the slope and b represents the y-intercept, we need to find the values of m and b using the given points (3, 1) and (1, -3).
First, we need to find the slope (m) using the formula:
m = (y2 - y1) / (x2 - x1)
Let's use the coordinates (3, 1) as (x1, y1) and (1, -3) as (x2, y2):
m = (-3 - 1) / (1 - 3)
m = (-4) / (-2)
m = 2
Now that we have the slope (m), we can substitute it and one of the points [(x1, y1) or (x2, y2)] into the equation y = mx + b to find the y-intercept (b).
Let's use the point (3, 1) as (x1, y1):
1 = 2(3) + b
1 = 6 + b
To solve for b, we can subtract 6 from both sides:
1 - 6 = b
-5 = b
So, the y-intercept is b = -5.
Now that we have the slope (m = 2) and the y-intercept (b = -5), we can write the equation in slope-intercept form:
y = 2x - 5
Comparing this to your answer, y = 2x + 5, it seems that there might have been a mistake in the book. The correct equation based on the given points is y = 2x - 5.