select the abbreviation that tells how the italicized noun clause is used.

s-subject, do-direct object, pn-predicate noun, op-object of preposition

a lecture on cleanliness was not what the children wanted to hear.

s
op
pn
do

There aren't any italicized noun clauses.

Explanation:

However, it is possible to explain something:

The subject is the doer of the action, in this case, a lecture.

The direct object is directly affected by the main verb, what the children.

The predicate noun is a noun or a phrase noun that renames the subject of a sentence after to be in any of its forms (present, past, participle), what the children wanted to hear.

The object of preposition is the noun or pronoun ruled by a preposition, cleanliness.

these have to be in your own words

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4