Completing the square, x² − 10x + 7 becomes
A(x − 5)² + 18
B(x − 10)² + 7
C(x + 5)² − 18
D(x − 5)² − 18
Answer & Solution
Correct answer: D. (x − 5)² − 18
Since (x − 5)² = x² − 10x + 25, subtracting 18 restores the constant 7.
Related questions
For x² − 6x + 5 = 0 the numerical value of |α − β| isWhich is a factorisation of 6x² + x − 2?Factoring x² + 7x + 12 = 0 by inspection gives rootsCircle, ellipse, parabola and hyperbola equations are quadratic inProblems solvable by quadratic equations were known as early asThe word quadratic comes from a Latin word meaningThe reduced form of 2x² + 6x + 4 = 0 isDividing a quadratic by a gives a reduced form with leading coefficient