Determine the standard form of the equation of the line that passes through (-6, 6) and (3, -2). A. -8x + 9y = -6 C. -8x -9y = 6
B. 8x + 9y = 6 D. 9x - 8y = 6
1 answer:
Answer:
B. 8x + 9y = 6
Step-by-step explanation:
You can eliminate answer choices A and C because their leading coefficient is negative. In standard form, the leading coefficient is positive.
For the remaining two equations, you can check to see if the given points are on the line
B: for point (-6, 6), we want 8(-6) +9(6) = 6 . . . true
for point (3, -2), we want 8(3) +9(-2) = 6 . . . . true
The appropriate equation is 8x +9y = 6.
D: (we don't need to check to know it won't work after the above)
__
The equation in standard form, can be written from ...
(Δy)(x -a) = (Δx)(y -b) . . . . . for some point (a, b)
The values of Δx and Δy are the differences between corresponding coordinates.
Δy = 6 -(-2) = 8
Δx = -6 -3 = -9
For point (-6, 6), the above equation becomes ...
8(x +6) = -9(y -6)
8x +48 = -9y +54 . . . . eliminate parentheses
8x +9y = 6 . . . . . . . . . . add 9y-48
You might be interested in