Math (Algebra/PreAlgebra)
posted by Samantha .
Which equation is an identity?
a. 3x  9 = 3x
b. 4p + 7 = 7 + 4p
c. 2w = 0
d. 5k = 5

What's an identity?

an identity is an equation which is true for all values of the variable
As a quick test, if you solve it, and you get a true statement, then it is an identity.
e.g. look at the first answer
3x  9 = 3x
9 = 0, which is NOT true, so Not an identity
but
4p + 7 = 7 + 4p
solving this we get
0 = 0 which is TRUE, so it is an identity. 
That makes so much sense! Thank you sooooooooo much! =]
Respond to this Question
Similar Questions

SHAY
THE MATH QUESTION IS IT ALGEBRA , PRE ALGEBRA' OR GEOMETRY? 
Algebra
My instructions are to solve the problem by showing the steps and identify as a conditional equation, an inconsistent equation or an identity. 0.06q + 14 = 0.3q  5.2 You can convert that to 0.24 x = 19.2 and solve it for x. The original … 
Algebra
Solve the equation identify as an identity, an inconsistent equation or a conditional. My equation is 13/2x+7/4 I know the answer is Conditional {2}, but I cannot figure out how to get it or even where to start. 
Algebra HELP!
Solve the equation identify as an identity, an inconsistent equation or a conditional. My equation is 13/2x+7/4 I know the answer is Conditional {2}, but I cannot figure out how to get it or even where to start. 
prealgebra
kk my teach told me to describe and draw things that are about prealgebra and she told me to write what prealgebra is... so can anyone help me? 
Math (Algebra/PreAlgebra)
What is the xintercept of the line with equation 2y + 3x = 24? 
pre algebra(MATH)
I need help with prealgebra solving equations by multiplying or dividing. Can you help me with this homework for free? 
algebra
If an equation is an identity, then the solution to that equation is _______. 
Math pre algebra please help
Solve the equation 1/2x 5 +2/3x=7/6+4 
Math pre algebra please help with ?
Solve the equation 1/2x 5 +2/3x=7/6x+4