Question

decide whether each of these is an expression, an equation or an identity.
a. 2p+2p+5-2+4p+3
b. 6n+7=3n+14
c. 9t+8-2(t-3)+5

Answer 1

There is no '=' sign in (a). What do you think about a ?

Answer 2

expression?

Answer 3

Yes. What about (c) ?

Answer 4

expression

Answer 5

Good! What about (b) ?

Answer 6

equation

Answer 7

Why not identity ?

Answer 8

because i don't know what an identity is and it has an equals sign

Answer 9

Equation and identity both have '=' sign ! Is (b) true for any value of n ? For instance take n = 1 and see if left hand side (LHS) = right hand side ?

Answer 10

no they don't equal the same

Answer 11

so is it an identity

Answer 12

No, (b) cannot be an identity because identity has '=' sign and is true for all the values the variable can take.
(b) is an equation because it has '=' sign is true for a certain value of n

Answer 13

ok ty