Advanced MathEasyRecovering a number from its square, in words
Advanced Math practice question
When a positive number is squared and the result is decreased by 11, the outcome is 70. What is the number?
Answer: 9
x² − 11 = 70 gives x² = 81, and the positive number is 9.
Common wrong answers
- If you answered 59
- Add the 11 back before taking the square root: x² = 81.
- If you answered 81
- 81 is the square; the number itself is 9.
- If you answered -9
- −9 squares to 81 too, but the number is stated to be positive.
More Advanced Math questions
- Easy
If f(x) = 3x − 7, what is the value of f(5)? - Easy
What are the solutions to x² − 9 = 0? - Easy
Which of the following expressions is equivalent to x² + 7x + 12 ? - Easy
The function g is defined by g(x) = x³ + 2x. What is the value of g(−2) ? - Easy
For x > 0, which of the following is equivalent to ∛(x⁵) ? - Easy
The function h is defined by h(x) = (x − 6)(x + 2). What is one value of x for which h(x) = 0 ?
Not affiliated with the College Board. SAT is a trademark of the College Board.