You could add them on a number line or count on your fingers.
Answer:
Answer c: 
Step-by-step explanation:
Hi there!
Let´s start writting the formula

If we multiplicate both sides by (x₂ - x₁):

Then if we add y₁ to both sides of the equation:

Then, the right answer is the answer c)
Have a nice day!
Answer:
y = 4x + 3
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m = 
with (x₁, y₁ ) = (- 1, - 1) and (x₂, y₂ ) = (0, 3)
m =
=
= 4
The line crosses the y- axis at (0, 3 ) ⇒ c = 3
y = 4x + 3 ← equation of line
Answer:
(-1,1)
Step-by-step explanation:
x + 9y = 8
-6x - 9y = -3
Add the two equations together to eliminate y
x + 9y = 8
-6x - 9y = -3
---------------------
-5x = 5
Divide by -5
-5x/-5 = 5/-5
x = -1
Now solve for y by substituting into the first equation
x+9y = 8
-1 + 9y =8
Add 1 to each side
-1+1 + 9y = 8+1
9y=9
Divide each side by 9
9y/9 = 9/9
y = 1