Advertisements
Advertisements
Question
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
Solution
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
RELATED QUESTIONS
The sum of the squares of the two consecutive odd positive integers as 394. Find them.
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.
If one of the equation ax2 + bx + c = 0 is three times times the other, then b2 : ac =
Solve the following equation: `10"x" - 1/"x" = 3`
Solve equation using factorisation method:
`x + 1/x = 2.5`
The length of verandah is 3m more than its breadth. The numerical value of its area is equal to the numerical value of its perimeter.
(i) Taking x, breadth of the verandah write an equation in ‘x’ that represents the above statement.
(ii) Solve the equation obtained in above and hence find the dimension of verandah.
Solve the following equation by factorization
`(2)/(x^2) - (5)/x + 2 = 0, x ≠ 0`
A rectangle of area 105 cm² has its length equal to x cm. Write down its breadth in terms of x. Given that the perimeter is 44 cm, write down an equation in x and solve it to determine the dimensions of the rectangle.
Two pipes running together can fill a tank in `11(1)/(9)` minutes. If one pipe takes 5 minutes more than the other to fill the tank, find the time in which each pipe would/fill the tank.
For equation `1/x + 1/(x - 5) = 3/10`; one value of x is ______.
