Transcript Expressions and Equations

Expressions and
Equations
Algebra I
2011-2012
Equations vs. Expressions
Expressions • Shows a mathematical
relationships
Ex.
• They cannot be
solved, it DOES NOT
2x+9
have an answer
5-9x+x-7 • We simplify
expressions
-(4+9x)
Equations vs. Expressions
Equations
Ex.
2x+9=2
5-9x+x-7=1
-(4+9x)=2
• Equates two
expressions
• They can be solved
• Isolate the variable
Step for Solving
Equations
Steps for
solving
equations
 Distribute
 Combine Like Terms
 Solve
Solving one  Step 1
and two steps  Add or subtract the CONSTANT
by using the inverse operation
equations
 Step 2
 Multiply or divide the coefficient
by using the inverse operation.
Step for Solving Multi Step Equations
What if
there are
variables on
both sides
of the
equal sign?
• Move VARIABLES to
one side of the = sign
by addition or
subtraction and
CONSTANTS to the
other.
• Then solve like a
normal equation.
Examples
Step for Solving
Equations
Combining
Like
Terms
To combine like terms, the
terms must have the same
variable or be constant.
5x and 6x can be combined
2x and 3y cannot be
combined
3x and 4 cannot be combined
To combine like terms you
add or subtract the
coefficient
Step for Solving
Equations
Distribution When distributing the
number on the outside of
the parenthesis multiply by
EVERYTHING on the
inside
REMEMBER YOUR RULES
FOR MULTIPLYING
NEGATIVE AND
POSITIVE NUMBERS
Step for Solving
Equations
What if
This is the same as having
there’s no
a 1 as a coefficient or in
coefficient
front.
or number in
Ex. x-1 = 1x-1
front of the
2-(t+6) = 2-1(t+6)
parenthesis?