Answer:
Ameliorate retort, pertaining to preceding albeit contingent interrogate proximates subject to x = 12.
Explanation:
Availing, exploiting, albeit maneuvering the Mathematic convention, Order of Operations (OO), the contiguous albeit proximate equation may ascertain as the preeminent imminent:
Groups: Not identified.
Exponents: Not identified, disparaging ₁.
Multiplication: Derived, pertaining to subtraction, 4 · (7/4x) = 4 · 21 7x = 84
Division: Derived, pertaining to multiplication, 7x = 84 ⇒ x = 12
Addition: Aggregate constants ⇒ 5/2x = 3/4x +21
Subtraction: Abate algebraic groups ⇒ 7/4x = 21