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
Solve the following quadratic equations by factorization:
`(2x)/(x-4)+(2x-5)/(x-3)=25/3`
Two number differ by 4 and their product is 192. Find the numbers?
A passenger train takes one hour less for a journey of 150 km if its speed is increased by 5 km/hr from its usual speed. Find the usual speed of the train.
Find the two consecutive positive even integers whose product is 288.
Solve the following quadratic equation by factorisation.
\[6x - \frac{2}{x} = 1\]
Solve the following quadratic equations by factorization:
\[\frac{1}{2a + b + 2x} = \frac{1}{2a} + \frac{1}{b} + \frac{1}{2x}\]
A quadratic equation whose one root is 2 and the sum of whose roots is zero, is ______.
The sum of two numbers is 9 and the sum of their squares is 41. Taking one number as x, form ail equation in x and solve it to find the numbers.
The perimeter of a rectangular plot is 180 m and its area is 1800 m2. Take the length of the plot as x m. Use the perimeter 180 m to write the value of the breadth in terms of x. Use the values of length, breadth and the area to write an equation in x. Solve the equation to calculate the length and breadth of the plot.
For equation `1/x + 1/(x - 5) = 3/10`; one value of x is ______.
