Keep in mind that whenever you have a variable inside an expression, you have to think of it as a placeholder, hiding a certain value which we haven't specified yet.
Expressions with variables are a mean to express the generic idea underneath the expression, rather than its particular value.
So, an expression like x-7 represents the idea of subtracting 7 from a particular number. Once you give a specific value to x, the expression will become an actual subtraction between numbers, and you will be able to compute its value.
So, we have several values for x, which are several ways to turn our "abstract" subtraction into an actual, computable subtraction.
If 
, the expression becomes 
and it evaluates to 
.
If 
, the expression becomes 
and it evaluates to 
.
If 
, the expression becomes 
and it evaluates to 
.
If 
, the expression becomes 
and it evaluates to 
.
If 
, the expression becomes 
and it evaluates to 
.
Answer:
small posters cost $2.30 each
large posters cost $4.95 each
Step-by-step explanation:
Let
price of large poster be "l", and
price of small poster be "s"
$16.80 for 2 large and 3 small, we can write:
2l + 3s = 16.80
Then,
$14.15 for 1 large and 4 small, we can write:
l + 4s = 14.15
We can write this as:
l = 14.15 - 4s
Now we substitute this expression for "l" into first equation and solve for s first:
small posters cost $2.30 each
Now, we know l = 14.15 - 4s, so
l = 14.15 -4(2.30)
l = 4.95
large posters cost $4.95 each
Answer:
C. ≥
Step-by-step explanation:
X(x+5)=234
x^2 +5x=234
x^2+5x-234=0
Factor:
x^2+5x-234
(x-13)(x+18)
the integers are 13 and 18.
