Parents who don't get concerned when their children make grammatical mistakes are probably aware of:

Social interaction theory

Explanation:

Social interaction theory is described as language development emphasis where there is an interaction between a child(who is still learning) and an adult(who is knowledgeable on language learning).

The parents having understood this theory don't get concerned when the children make mistakes because they see it as part of the leaning process

x = 7

step-by-step explanation:

equating the expression for area to the given area

2x² - 7x - 4 = 45 ( subtract 45 from both sides )

2x² - 7x - 49 = 0 ← in standard form

to factor consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term

product = 2 × - 49 = - 98 and sum = - 7

the factors are - 14 and + 7

use these factors to split the middle term

2x² - 14x + 7x - 49 = 0 ( factor the first/second and third/fourth terms )

2x(x - 7) + 7(x - 7) = 0 ← factor out (x - 7)

(x - 7)(2x + 7) = 0

equate each factor to zero and solve for x

x - 7 = 0 ⇒ x = 7

2x + 7 = 0 ⇒ 2x = - 7 ⇒ x = -

thus the positive value for x is x = 7