Both of these are ways to express linear equations.
is the equation for a line with slope <em>m</em> which contains the point 
. This is called point-slope form.
is the equation for a line with slope <em>m</em> and y-intercept b. That is, it contains the point (0, b). This is called slope-intercept form.
Both of these are perfectly valid ways of writing lines, though sometimes one will be easier to use than the other.
Answer:
the equation is
x - 4 = - 9
the number is
-5
Step-by-step explanation:
First, we don't know the number so we represent it with a variable like "x".
then difference simply means subtraction.
" is" simply means = ( equal to)
so the question says that difference of 4 and a number is 9 so we have x - 4 = -9
so now let's solve for x
we group liked terms and make x stand alone.
x = -9 + 4
( +4 because it crossed an equal sign)
x = - 5
we have
x = -5
so we can substitute the -5 into the equation to if its true
from the equation x - 4 = - 9
where we put -5 instead of x
-5 - 4 = - 9
Answer:
The answer to your question is x = 2, y = -1, z = 3
Step-by-step explanation:
Data
x + y + z = 4
x - 2y - z = 1
2x - y - 2z = -1
Solve the system of equations
| 1 1 1 |
| 1 -2 - 1 |
Δ = | 2 -1 -2| = (4 - 1 -2) - (-2 + 1 -4) = 1 + 5 = 6
| 1 1 1 |
| 1 -2 -1 |
| 4 1 1 |
| 1 -2 -1 |
Δx = |-1 -1 -2| = (16 - 1 + 1) - (-2 + 4 + 2) = 16 + 4 = 12
| 4 1 1 |
| 1 -2 -1 |
| 1 4 1 |
| 1 1 -1 |
Δy = | 2 - 1 -2 | = (-2 -1 -8) - (-8 + 1 + 2) = -11 - 5 = -6
| 1 4 1 |
| 1 1 -1|
| 1 1 4|
| 1 -2 1|
Δz = | 2 -1 -1| = (2 - 4 + 2) - (-1 -1 -16) = 0 + 18
| 1 1 4|
| 1 -2 1|
Find x, y and z
x = Δx/ Δ = 12/6 = 2
y = Δy/Δ = -6/6 = -1
z = Δz/Δ = 18/6 = 3
