Question
If 9x² + y² = 37 and xy=2, x, y>0, then the
value of (27x³ + y³) is:Solution
27x3 + y3 = (3x + y) (9x2 + y2 – 3xy) = use (a + b)2 = a2 + b2 + 2ab = (3x + y)2 = ax2 + y2 + 6xy = (3x + y)2 = 37 + 6 × 2 = 49 = 3x + y = 7 = 27x3 + y3 = 7 × (37 – 3 × 2) = 27x3 + y3 = 7 × 31 = 217
In each of the following questions, choose that set numbers from the four alternative sets, that is similar to the given set.
Given set:Â [92...
‘Spinach’ is related to ‘Herb’, in the same way as ‘Mango’ is related to ‘____’.
(The word must be considered as meaningful Englis...Select the option that is related to the first number in the same way as the third number is related to fourth number and the fifth number is related to...
In a certain code language, ‘plant is life’ is written as ‘ni vi di, ‘get me plant’ is written as ‘hi di ri’, and ‘get is tree’ is wri...
- Select the option that is related to the third term in the same way as the second term is related to the first term and the sixth term is related to the fi...
Select the option that is NOT like the given set.
(8, 40, 56)
WORD : 3584 :: PLAN : 6214 :: CODE : ?
Select the option that is related to first number in the same way third number is related to forth number.
26: ? :: 34: 1224
65 : 31 :: 72 : ? :: 34 : 13
Hard : Stone :: Soft : ?
