MCQ
The factors of x3 - 7x - 6 are.
- Ax(x - 6) (x - 1)
- B(x - 1) (x - 3) (x + 2)
- C(x + 1) (x + 2) (x - 3)
- D(x2 - 6) (x - 1)
✓
Answer
- (x + 1) (x + 2) (x - 3)
Solution:
The given expression to be factorized is x3 - 7x + 6
This can be written in the form
x3 - 7x + 6 = x3 - (1 + 6)x + 6
= x3 - x - 6x + 6
Take common x from the first two terms and -6 from the last two terms.
Then we have,
x3 + 7x + 6 = x(x2 - 1) - 6(x - 1)
= x{(x)2 - (1)2} - 6{x - 1}
= x(x + 1)(x - 1) - 6(x - 1)
Finally, take common (x - 1) from the above expression,
x3 - 7x + 6 = (x - 1) {(x + 1) - 6}
= (x - 1) (x2 + x - 6)
= (x - 1) (x2 + 3x - 2x - 6)
= (x - 1) {x(x + 3) - 2(x + 3)}
= (x - 1) (x + 3) (x - 2)
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The simplest rationalisation factor of $(2\sqrt{2}-\sqrt{3})$ is:
→In the given figure, O is the centre of a circle and chords AC and BD intersect at E. If $\angle\text{AEB}=110^\circ$ and $\angle\text{CBE}=30^\circ,$ then $\angle\text{ADB}=?$
→- 70°
- 60°
- 80°
- 90°
Let $\bar{\text{x}}$ be thae mean of x1, x2, ......, xn, and $\bar{\text{y}}$ the mean of y1 , y2 , ... , yn . If $\bar{\text{z}}$ is the mean of x1 , x2 , ... , xn , y1 , y2, ... , yn, then $\bar{\text{z}}$ is equal to:
→- $\bar{\text{x}}+\bar{\text{y}}$
- $\frac{\bar{\text{x}}+\bar{\text{y}}}{2}$
- $\frac{\bar{\text{x}}+\bar{\text{y}}}{\text{n}}$
- $\frac{\bar{\text{x}}+\bar{\text{y}}}{2\text{n}}$
The mid-value of a class interval is 42. If the class size is 10, then the upper and lower limits of the class are:
Euclid stated that all right angles are equal to each other in the form of
The value of y at x = -1 in the equation 5y = 2 is:
The area of the figure ABCD formed by joining A (-1, 1), B (5, 1), C (5, 6) and D (-1, 6) is
