Answer:
The number being multiplied by
x
is the slope of the line. So, the slope of the line is calculated by rise/run. The rise is how up or down it goes from a certain point to another, and the run is how right or left it goes from a certain point to the other.
(3, -2)
Step-by-step explanation:
y = -2x + 4
-x + 3y = -9
-x + 3 (-2x + 4) = -9
-x + -6x + 12 = -9
-7x = - 9 – 12
-7x = - 21
X = 3
We substitute x with 3 to evaluate y;
-3 + 3y = -9
3y = -6
y = -2
Elimination Method;
y = -2x + 4
-x + 3y = -9
We arrange the equations for substitution;
2x + y = 4
-x + 3y = -9
We multiply the first equation with 3 so we can substract one variable to zero;
3 (2x + y = 4)
= 6x + 3y = 12
Then we subtract the two;
6x + 3y = 12
-x + 3y = -9
7x = 21
x = 3
We evaluate y by substitution x with 3 in one of the equation;
-x + 3y = -9
-3 + 3y = -9
3y = -6
y = -2
The final answer expressed as a coordinate point is;
(3, -2)
Let's say we placed dominoes close together such that they only fell over one way: to the right hand side. Let's call the dominoes A and B.
Domino A is to the left of domino B. If we push over domino A, then it will hit domino B to cause it to fall over as well. We have a mini chain reaction of sorts. The fall of A triggers the fall of B, but not the other way around.
For this problem, we can think of domino A as "Jillian gets a raise" and domino B as "she will buy a new car". The raise causes her to get a new car, but not vice versa.
Since we're told in the last sentence she definitely got the raise, this must mean she will definitely get the new car.
In terms of symbols, the law of detachment is stated as
- If P, then Q
- P is true
- Therefore Q is true
Side note: some books might use the term "modus ponens" instead of "law of detachment". They're the same thing.
12 eggs for $1.12
3 eggs for $?
As you can see, to get from 12 eggs to 3 eggs, you divide by 4, so do the same with $1.12 to get $0.28
The cost of 3 eggs is $0.28