Advertisements
Advertisements
प्रश्न
`8x^2-14x-15=0`
Advertisements
उत्तर
`8x^2-14x-15=0`
⇒`16x^2-28x-30=0`
⇒`16x^2-28x=30`
⇒`(4x)^2-2xx4x xx7/2+(7/2)^2=30+(7/2)^2`
⇒`(4x-7/2)^2=30+49/4=169/4=(13/2)^2`
⇒`4x-7/2=+-13/2`
⇒`4x=7/2=13/2 or 4x-7/2=13/2`
⇒`4x=13/2+7/2=20/2=10 or 4x=-13/2+7/2=6/2=-3`
⇒`x=5/2 or x=-3/4`
Hence, `5/2 and -3/4` are the roots of the given equation.
APPEARS IN
संबंधित प्रश्न
Solve the following quadratic equations by factorization:
4x2 + 4bx - (a2 - b2) = 0
Solve the following quadratic equations by factorization:
`x^2-4sqrt2x+6=0`
A fast train takes one hour less than a slow train for a journey of 200 km. If the speed of the slow train is 10 km/hr less than that of the fast train, find the speed of the two trains.
A takes 10 days less than the time taken by B to finish a piece of work. If both A and B together can finish the work in 12 days, find the time taken by B to finish the work.
A dealer sells an article for Rs. 24 and gains as much percent as the cost price of the article. Find the cost price of the article.
Solve each of the following equations by factorization:
`9/2x=5+x^2`
Determine whether the values given against the quadratic equation are the roots of the equation.
x2 + 4x – 5 = 0 , x = 1, –1
One of the roots of equation 5m2 + 2m + k = 0 is `(-7)/5` Complete the following activity to find the value of 'k'.
The positive value of k for which the equation x2 + kx + 64 = 0 and x2 − 8x + k = 0 will both have real roots, is
A quadratic equation whose one root is 2 and the sum of whose roots is zero, is ______.
Solve the following equation: 2x2 - 3x - 9=0
Solve the following equation: a2b2x2 + b2x - a2x - 1 = 0
Solve the equation using the factorisation method:
`(3x -2)/(2x -3) = (3x - 8)/(x + 4)`
Car A travels x km for every litre of petrol, while car B travels (x + 5) km for every litre of petrol.
Write down the number of litres of petrol used by car A and car B in covering a distance of 400 km.
Solve the following quadratic equation by factorisation:
x2 + 3x - 18 = 0
Solve for x:
`(x + 1/x)^2 - (3)/(2)(x - 1/x)-4` = 0.
In each of the following determine whether the given values are solutions of the equation or not.
x2 + 6x + 5 = 0; x = -1, x = -5
In each of the following, determine whether the given values are solution of the given equation or not:
x2 + x + 1 = 0; x = 0; x = 1
Solve the following equation by factorization
`x^2/(15) - x/(3) - 10` = 0
For equation `1/x + 1/(x - 5) = 3/10`; one value of x is ______.
