Question

She invited him to her house yesterday.(change into passive voice)

Answer 1

We use the Passive Voice of a verb when the subject of the verb, referring to the person or thing, is affected by the action described by the verb. Only a verb which can take an object can be converted into the Passive Voice.

Since the given sentence ‘She invited him to her house yesterday’ is in Past Simple tense, we will use the passive verb of the Past Simple tense. So the correct passive sentence of the given sentence is as follows:

HE WAS INVITED TO HER HOUSE YESTERDAY BY HER.

Answer 2

Active sentences in the past simple tense have the following structure :

# Subject + Past tense form of the verb + Object

Passive sentences in the past simple tense have the following structure :

Object of the active sentence + Was/Were + Past Participle form of the verb + by + Subject of the active sentence
Now the question, 

Sentence in Active Voice -
She invited him to her house yesterday.

Sentence in Passive voice will be -
He was invited by her to her house yesterday.