Answer:
The original price of her purchase was $65.
Step-by-step explanation:
From the information given, you know that $13 represents 20% of the original price and you can use a rule of three to find the value that represents 100%, which would be the original pice of her purchase:
$13 → 20%
x ← 100%
x=(13*100)/20
x=1300/20
x=65
According to this, the answer is that the original price of her purchase was $65.
Do you have to use substitution?
To isolate c means to separate it completely on one side of the equals sign.
To isolate variables, you apply opposite operations.
In E = mc², m and c are being multiplied together. To separate them, you divide by the variable you want to get rid of. However, you must do this to both sides of the equation always. Whatever you do to one side of the equation you must do to the other side as well. This is so the equation remains true.
Since we want to isolate c, we'll start by dividing both sides by m.
E = mc²
E/m = mc²/m
E/m = c² -- The m's cancel as 1
Now we have c squared. The opposite of squaring something is taking its square root. Take the square root of each side.
E/m = c²
√(E/m) = √(c²)
√(E/m) = c -- Opposite operations cancel each other out
And you've isolated c!
Answer:
c = √(E/m)
A system that will produce infinitely many solutions will have the property where all the equations overlap. That means they will have the same slope and y-intercept.
An easy way to determine if they will produce infinitely many solutions is to put all the equations into
form. If everything is the same, you know it will have infinite solutions.
