Advertisements
Advertisements
प्रश्न
Factorize each of the following algebraic expression:
x2 − 4x − 21
Advertisements
उत्तर
\[\text{ To factorise }x^2 - 4x - 21,\text{ we will find two numbers p and q such that }p + q = - 4\text{ and }pq = - 21 . \]
Now,
\[3 + ( - 7) = - 4 \]
and
\[3 \times ( - 7) = - 21\]
\[\text{ Splitting the middle term }- 4x\text{ in the given quadratic as }- 7x + 3x, \text{ we get: }\]
\[ x^2 - 4x - 21 = x^2 - 7x + 3x - 21\]
\[ = ( x^2 - 7x) + (3x - 21)\]
\[ = x(x - 7) + 3(x - 7)\]
\[ = (x + 3)(x - 7)\]
APPEARS IN
संबंधित प्रश्न
Factorize each of the following algebraic expressions:
2r(y − x) + s(x − y)
Factorize each of the following algebraic expressions:
6(a + 2b) −4(a + 2b)2
Factorize each of the following algebraic expressions:
(2x − 3y)(a + b) + (3x − 2y)(a + b)
Factorize each of the following algebraic expression:
4x2 + 12xy +9y2
Factorize each of the following algebraic expression:
96 − 4x − x2
Factorize each of the following algebraic expression:
a2 − 8ab + 16b2 − 25c2
Factorise the following expression and write in the product form.
tr2s3
Factorise the following expression.
`9"x"^2-1/16"y"^2`
Factorise the following expression.
`1/2y^2-8z^2`
Factorise the following expressions and write them in the product form.
5t2
