Question

solve x3-7x+6 please solve it is urgent​

Answer 1

Answer:

(x - 1)(x + 3)(x - 2)

Step-by-step explanation:

Given : x³ - 7x + 6

Step I : Add and subtract x².

→ x³ - 7x + 6 + x² - x²

Rearranging the terms.

→ x³ - x² + x² - 7x + 6

We can write this as :

→ x²(x - 1) + x² - 7x + 6

Step II : Using Middle Term Factorisation.

→ x²(x - 1) + x² - x - 6x + 6

Taking common terms out.

→ x²(x - 1) + x(x - 1) - 6(x - 1)

→ (x - 1)(x² + x - 6)

Step III : Again, using Middle Term Factorisation.

→ (x - 1)(x² + 3x - 2x - 6)

→ (x - 1) [ x(x + 3) - 2(x + 3) ]

→ (x - 1) [ (x + 3)(x - 2) ]

Opening the brackets.

→ (x - 1)(x + 3)(x - 2)

• In Middle Term Factorisation, we factorise the middle term only.
• First we multiply 'a' and 'c'.
• Then we have to find such a pair of number such that on addition or subtraction, the result equals to 'b' and on multiplication, the result equals to the multiplication of 'a' and 'c'.