Explain best you can and if possible please just give answers i have to go to sleep dont know if i can finish in morning
A linear equation has the form y=mx+c.
In the first set you are given m. Substitute the points and then rearrange to find c. So for the first question,
y = -2x+c and (x,y) = (2,1)
1 = -2(2)+c
1=-4+c
1+4 =c
c=5.
y = -2x+5
In the second set you are given 2 points. Call them $\displaystyle (x_1,y_1)$ and $\displaystyle (x_2, y_2)$, and use the formula $\displaystyle m = \frac{y_2-y_1}{x_2-x_1}$, then use the method for the first set.
The first question looks like this:
$\displaystyle (x_1,y_1) = (2,3)$ and $\displaystyle (x_2,y_2) = (5,9)$
$\displaystyle m = \frac{9-3}{5-2} $
$\displaystyle =\frac{6}{3}$
=2
y = 2x+c
3=2(2)+c
3=4+c
3-4 = c
c=-1
y=2x-1
This is not a site for doing your homework.
Option 1: Use the model $\displaystyle y - y_1 = m (x - x_1)$.
For m = 3 and (-1, -10): $\displaystyle y - (-10) = 3 (x - (-1)) \Rightarrow y = 3x - 7$.
Option 2: Use the model $\displaystyle y = mx + c$.
For m = 3 and (-1, -10): $\displaystyle y = 3x + c$. Substitute (-1, -10) and solve for c: -10 = -3 + c => c = -7.
Note that f(5) = -1 etc. means that the point (5, -1) lies on the line.