Question

Which of the following quadratic equations is not solvable by grouping?(1 point)
Responses

x2−2x+1=0
x squared minus 2 x plus 1 equals 0

2x2−2x−10=0
2 x squared minus 2 x minus 10 equals 0

2x2+14x+12=0
2 x squared plus 14 x plus 12 equals 0

x2−12x+35=0

Answer 1

2x^2 − 2x − 10 = 0

Reason: For factoring by grouping you need two numbers whose product = a*c and sum = b.
- 2x^2−2x−10: a*c = −20, need two numbers summing to −2 — none exist (discriminant = 21, not a perfect square), so it cannot be factored by grouping.
- The others factor: x^2−2x+1=(x−1)^2; 2x^2+14x+12=2(x+1)(x+6); x^2−12x+35=(x−5)(x−7).