Question

4/a-b+4/b+b/(a-b)^2 при а=9 ;b=4

Answer 1

4/9-4+4/4+4/(9-4)^2=4/9-4+1+4/81-106+16=
4/9-3+4/-9
4/9-4/9-3=-3

Answer 2

To evaluate the expression 4/a - b + 4/b + b/(a-b)^2 with a = 9 and b = 4, follow these steps:

Step 1: Substitute the values of a and b into the expression. Step 2: Perform the calculations.

Let's go through it step by step:

Step 1: Substitute a = 9 and b = 4 into the expression:

4/a - b + 4/b + b/(a-b)^2

Now, plug in the values:

4/9 - 4 + 4/4 + 4/(9-4)^2

Step 2: Perform the calculations:

1. 4/9 - 4 = 4/9 - 36/9 = -32/9
2. 4/4 = 1
3. (9-4)^2 = 5^2 = 25
4. b/(a-b)^2 = 4/25

Now, combine all the results:

-32/9 + 1 + 4/25

To add fractions, we need a common denominator:

Step 3: Find the common denominator and convert the fractions:

The common denominator for 9 and 25 is 225 (9*25). Convert all fractions to have a denominator of 225:

(-32/9)(25/25) + (1)(225/225) + (4/25)*(9/9)

Now, perform the calculations:

(-3225 + 225 + 49)/225 (-800 + 225 + 36)/225 (-539)/225

The final result is approximately:

-2.39556

So, when a = 9 and b = 4, the expression 4/a - b + 4/b + b/(a-b)^2 evaluates to approximately -2.39556.