2022 · Q23
If squaring a positive real number x is same as adding 12 in it, then what is x equal to?
Elementary MathematicsAlgebra
- A2
- B3
- C4
- D5
Explanation
x² = x+12 gives x²-x-12 = 0, i.e. (x-4)(x+3) = 0. The positive root is x = 4. Hence the keyed option is C.