Advertisements
Advertisements
Question
Solve the following equation by factorization
21x2 – 8x – 4 = 0
Advertisements
Solution
21x2 – 8x – 4 = 0
⇒ 21x2 - 14x + 6x - 4 = 0
⇒ 7x (3x - 2) + 2 (3x - 2) = 0
⇒ (3x - 2) (7x + 2) = 0
Either 3x - 2 = 0,
then 3x = 2
⇒ x = `(2)/(3)`
or
7x + 2 = 0,
then 7x = -2
⇒ x = `(-2)/(7)`
Hence x = `(2)/(3), (-2)/(7)`.
APPEARS IN
RELATED QUESTIONS
The numerator of a fraction is 3 less than its denominator. If 2 is added to both the numerator and the denominator, then the sum of the new fraction and original fraction is `29/20`. Find the original fraction.
`x^2-6x+3=0`
If the equation ax2 + 2x + a = 0 has two distinct roots, if
Three consecutive natural numbers are such that the square of the first increased by the product of other two gives 154. Find the numbers.
Solve equation using factorisation method:
x(x – 5) = 24
A two digit number is such that the product of its digit is 14. When 45 is added to the number, then the digit interchange their places. Find the number.
Solve the following by reducing them to quadratic form:
`sqrt(y + 1) + sqrt(2y - 5) = 3, y ∈ "R".`
In each of the following determine whether the given values are solutions of the equation or not.
3x2 - 2x - 1 = 0; x = 1
Solve the following equation by factorization
2x2 – 8x – 24 = 0 when x∈I
Solve the following equation by factorization
`(x + 1)/(x - 1) + (x - 2)/(x + 2)` = 3
