Timer
00:00
Answers
A
B
C
D
E
Stats
Difficulty—
The equation of a straight line containing the points (10, 100) and (15, 60) is?
$$A. y=-8x+80$$
$$B. y=8x-180$$
$$C. \dfrac{x}{8} + 7.5$$
$$D. -8x-180$$
$$E. -\dfrac{x}{8} + 22.5$$
The OA is A.
We can use the equation,
$$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}\cdot(x-x_1)$$
Then,
$$y-100=\dfrac{60-100}{15-10}\cdot(x-10)$$
$$y-100=\dfrac{-40}{5}\cdot(x-10)$$
$$y-100=-8x +80$$
$$y=-8x + 180$$
Option A.
Please, can anyone explain another way to solve this PS question? Thanks!
$$A. y=-8x+80$$
$$B. y=8x-180$$
$$C. \dfrac{x}{8} + 7.5$$
$$D. -8x-180$$
$$E. -\dfrac{x}{8} + 22.5$$
The OA is A.
We can use the equation,
$$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}\cdot(x-x_1)$$
Then,
$$y-100=\dfrac{60-100}{15-10}\cdot(x-10)$$
$$y-100=\dfrac{-40}{5}\cdot(x-10)$$
$$y-100=-8x +80$$
$$y=-8x + 180$$
Option A.
Please, can anyone explain another way to solve this PS question? Thanks!
