Julio L. answered • 01/18/21
Elementary Math Tutor ( PK-6th )
To evaluate an algebraic expression means to find the value of the expression when the variable is replaced by a given number. To evaluate an expression, we substitute the given number for the variable in the expression and then simplify the expression using the order of operations.
An expression is a sentence with a minimum of two numbers and at least one math operation.
How do you write a VARIABLE EXPRESSION?
Example:
10 and a Number
10 + N
In the above case or situation the word expression is ten ( 10 ) and a number ( N )
If we add or substitute in place of N any number the word expression would hold true
What is a variable?
A defining variable is a symbol, such as x, used to describe any number. When a variable is used in an function, we know that it is not just one constant number, but that it can represent many numbers. ... A variable is a letter or a symbol used to represent any number.
YOUR QUESTION?
MATHEMATICS IS NUMBERS, LETTERS AKA SYMBOLS, AND OR OTHER.
WE SOLVE PROBLEMS FROM LEFT TO RIGHT MOST OF TIME
I GUESS FIRST THINGS FIRST AND SO ON
In math we also tend to use some ORDER OF OPERATIONS.
YOUR QUESTION?
Evaluate -2x 2 y, if x = -3 and y = -1.
YOUR POSSIBLE
ANSWERS
-12
-18
18
12
-2X2Y
X is equals to -3
Y is equal to -1
What are the steps to EVAUATE AN EXPRESSION
An expression consists of numbers, variables, and operations.
When you look at expression -2x 2y you can tell that -2 is x number of times ( -3 ) and 2 is y number of times ( -1 ).
Numbers -2 and 2
Variables x and y ( 2 different ones )
Operation? More than likely all multiplication and no addition or subtraction
Write
-2x 2y
Replace variables with their assigned given value in parenthesis is suggested
-2x 2y
-2( ) 2( )
-2(-3) 2(-1)
6 -2
-12
