Advertisements
Advertisements
प्रश्न
A two digit number is such that the product of its digit is 8. When 18 is subtracted from the number, the digits interchange its place. Find the numbers.
Advertisements
उत्तर
Let this two digit number be xy. Which means x=10x (as it comes in tens digit).
Then as per the question,
xy = 8, ....... (i)
l0x + y - 18 = 10y + x
⇒ 9x-9y-18=0
⇒ x - y - 2 = 0 ....... (ii)
Putting x = `8/"y"` from (i) in (ii) , we get ,
`8/"y" - "y" - 2 = 0`
⇒ y2 + 2y - 8 = 0
⇒ (y-2)(y+4 ) =O
⇒ y = 2, hence from (i), x=4.
Hence the number is 42
APPEARS IN
संबंधित प्रश्न
The area of a right angled triangle is 165 m2. Determine its base and altitude if the latter exceeds the former by 7 m.
Solve:
(a + b)2x2 – (a + b)x – 6 = 0; a + b ≠ 0
`4x^2+4sqrt3x+3=0`
The sum of the squares to two consecutive positive odd numbers is 514. Find the numbers.
If \[1 + \sqrt{2}\] is a root of a quadratic equation will rational coefficients, write its other root.
Three years ago, a man was 5 times the age of his son. Four years hence, he will be thrice his son's age. Find the present ages of the man and his son.
Solve the following quadratic equation by factorisation:
(x - 4) (x + 2) = 0
By selling an article for Rs. 21, a trader loses as much per cent as the cost price of the article. Find the cost price.
Find the roots of the following quadratic equation by the factorisation method:
`2x^2 + 5/3x - 2 = 0`
If α and β are roots of the quadratic equation x2 – 7x + 10 = 0, find the quadratic equation whose roots are α2 and β2.
