S. Two natural numbers differ by 3 and their product is 504. Find the
numbers.
9. Find two consecutive multiples of 3 whose product is 648.
Answers
Answer:
Let two numbers be x and y
x - y = 3 ------(1)
and xy = 504 ------(2)
then from first x = y + 3 -------(3)
Putting value of eq(3) in eq (2)
(y + 3) y = 504
y2 + 3y - 504 = 0
y2 + ( 24 - 21 ) y -504 = 0
y2 + 24y -21y -504 = 0
y ( y + 24 ) - 21 ( y + 24 ) = 0
( y - 21 ) ( y + 24 )
y = 21 or y = -24
then putting this value of y in eq(1)
we get x = 24 or x = - 21
Step-by-step explanation:
1 question is above
2 question is below
Let the required consecutive multiples of 3 be 3x and 3(x + 1).
According to the given condition,
3x×3(x+1)=648⇒9(x2+x)=648⇒x2+x=72⇒x2+x−72=0
⇒x2+9x−8x−72=0⇒x(x+9)−8(x+9)=0⇒(x+9)(x−8)=0⇒x+9=0 or x−8=0
⇒x=−9 or x=8
∴ x = 8 (Neglecting the negative value)
When x = 8,
3x = 3 × 8 = 24
3(x + 1) = 3 × (8 + 1) = 3 × 9 = 27
Hence, the required multiples are 24 and 27.