Advertisements
Advertisements
प्रश्न
Solve the following quadratic equation using formula method only
x2 - 7x - 5 = 0
Advertisements
उत्तर
x2 - 7x - 5 = 0
a = 1 ; b = -7 ; c = -5
D = b2 - 4 ac
= (-7)2 - 4(1)(-5)
= 49 + 20
= 69
x = `(- "b" ± sqrt ("b"^2 - 4 "ac"))/(2a)`
x = `(7 +- sqrt 69)/2`
x = `(7 + sqrt 69)/2` , x = `(7 - sqrt 69)/2`
APPEARS IN
संबंधित प्रश्न
Rs. 9000 were divided equally among a certain number of persons. Had there been 20 more persons, each would have got Rs. 160 less. Find the original number of persons.
`8x^2-14x-15=0`
One of the roots of equation 5m2 + 2m + k = 0 is `(-7)/5` Complete the following activity to find the value of 'k'.
If one of the equation x2 + ax + 3 = 0 is 1, then its other root is
The sum of the square of 2 positive integers is 208. If the square of larger number is 18 times the smaller number, find the numbers.
Solve the equation using the factorisation method:
`(3x -2)/(2x -3) = (3x - 8)/(x + 4)`
The sum of the squares of three consecutive natural numbers is 110. Determine the numbers.
By increasing the speed of a car by 10 km/hr, the time of journey for a distance of 72 km. is reduced by 36 minutes. Find the original speed of the car.
The speed of an express train is x km/hr arid the speed of an ordinary train is 12 km/hr less than that of the express train. If the ordinary train takes one hour longer than the express train to cover a distance of 240 km, find the speed of the express train.
A shopkeeper purchases a certain number of books for Rs. 960. If the cost per book was Rs. 8 less, the number of books that could be purchased for Rs. 960 would be 4 more. Write an equation, taking the original cost of each book to be Rs. x, and Solve it to find the original cost of the books.
