Which algebraic expression is a difference with two terms

The algebraic expression which is a difference of two terms is:

                   B.    5y-7

We know that any algebraic expression is a difference of two terms if there are two terms in an expression which are separated by a subtraction sign.

A)

              3y+1

In this expression we have two terms 3y and 1 which are separated by a addition sign.

Hence, option: A is incorrect.

B)

              5y-7

In this expression we have two terms as 5y and 7 which are separated by a negative sign or a subtraction sign.

                         Hence, option: B is correct.

C)

                -2y+5+3

In this expression we have three terms  "2y", "5" and "3"

Hence, this option is incorrect.

D)

             5(y-6)

Here we have two terms 5 and (y-6) which are separated by a multiplication sign.

Hence, option: D is incorrect.

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify

the answer would be d

straight away you can eliminate a and c because not all books contain a scientific skill because some may be fiction. c is also wrong because it saids that the only way children can learn is through books which is incorrect.

b is also wrong because reading can be a scientific skill but not always, therefore it is wrong which leaves you with d, the correct answer since it said that it can children learn.

hope this ! : 3