Find the approximate value of x from the given expression: 29.38 × 37.05 ÷ x +…
2024
Find the approximate value of x from the given expression:
29.38 × 37.05 ÷ x + 7.45 = 100.5
- A.
45
- B.
23
- C.
11
- D.
12
Attempted by 2 students.
Show answer & explanation
Correct answer: D
Concept:
To find an unknown x in an equation of the form (a × b) ÷ x + c = d, first isolate the term containing x by moving the constant c to the other side, then invert the division to convert it into a simple multiplication for x. Approximate the final quotient only at the very last step, after all algebraic rearrangement is complete.
Application:
Write the given equation: 29.38 × 37.05 ÷ x + 7.45 = 100.5
Subtract 7.45 from both sides to isolate the term with x: 29.38 × 37.05 ÷ x = 100.5 − 7.45 = 93.05
Multiply both sides by x and divide by 93.05 to isolate x: x = (29.38 × 37.05) ÷ 93.05
Compute the numerator: 29.38 × 37.05 = 1088.529
Divide: x = 1088.529 ÷ 93.05 ≈ 11.698
Round the quotient to the nearest whole number, as the question asks for an approximate value: x ≈ 12
Cross-check:
Substituting the unrounded value x = 11.698 back into the original expression gives 1088.529 ÷ 11.698 + 7.45 = 93.05 + 7.45 = 100.5, which matches the right-hand side exactly — confirming the rearrangement is correct before rounding.
Hence, the approximate value of x is 12.