Question

15. What is the equation that contains the coordinates (8,4) and (2,1)?

A. y = 2x - 3
B. y = 1/2x - 1
C. y = 1/2x
D. y = -1/2x + 8

I think it's B?

Answer 1

No it cant be B because when 8 is substitute for x the left sides solves as 4-1 which = 3 and the left side is 4. The way to check is to plug in the numbers, x being the first is the paratheses and y being the second, to the x and y in the equation.

Answer 2

IMPORTANT LINE RELATED EQUATIONS TO KNOW AND MEMORIZE

slope formula
m= slope/ gradiant -- same thing
\[m=\frac{y_2-y_1}{x_2-x_1}\]

standard formula
\[Ax+By=C\]

point-slope formula
\[y-y_1=m(x-x_1)\]

slope-intercept formula
b= y-intercept -- in the form of (0,y)

\[y=mx+b\]

Answer 3

first find the slope, then substitute the slope and a point into the point slope equation, then solve for slope intercept form

Answer 4

y=mx+b
y=1/2x+b
(2,1)
1=1/2*2+b
1=1+b
b=1-1
b=?

Answer 5

i assume so