Answer:
see explanation
Step-by-step explanation:
Given that y varies inversely as x then the equation relating them is
y = 
← k is the constant of variation
To find k use the condition y = 5 , x = 21
k = yx = 5 × 21 = 105
y = 
← equation of variation
When x = 10, then
y = 
= 10.5
Answer:
3ab
-------------------
(b+a)
Step-by-step explanation:
3/a - 3/b
-------------------
1/a^2 - 1/b^2
Multiply the top and bottom by a^2 b^2/ a^2/b^2 to clear the fractions
(3/a - 3/b) a^2 b^2
-------------------
(1/a^2 - 1/b^2) a^2b^2
3ab^2 - 3 a^2 b
-------------------
b^2 - a^2
Factor out 3ab on the top
3ab( b-a)
-------------------
b^2 - a^2
The bottom is the difference of squares
3ab( b-a)
-------------------
(b-a) (b+a)
Cancel like terms from the top and bottom
3ab
-------------------
(b+a)
Answer:
1/6
Step-by-step explanation:
The product will only be of the required form if the two chosen factors are of the form (x +by) and (x -by).
For the factor (x+y), there is also a factor (x-y) on the list. For the factor (x+5y), there is no factor (x-5y) available.
So, of the (4·3)/2 = 6 possible ways to choose two expressions from the four given expressions, only one pair of the 6 will have a product of the required form.
The probability is 1/6.
Answer:
b^-6
Step-by-step explanation:
(b^-2) / (b^4) = b^(-2 - 4)
