We can let
a = 1/(x-1)
b = 1/(y+2)
and rewrite the equations as
2a - b = 10
a + 3b = -9
Using the first to write an expression for b, we get
b = 2a - 10
Substituting this into the second equation gives
a + 3(2a -10) = -9
7a -30 = -9 . . . . . . . . simplify
7a = 21 . . . . . . . . . . .add 30
a = 3
b = 2·3 - 10 = -4

Now, we can find x and y.
   3 = 1/(x -1)
   x - 1 = 1/3
   x = 1 1/3 = 4/3

  -4 = 1/(y +2)
  y +2 = -1/4
  y = -2 1/4 = -9/4

Then the desired sum is
  x + y = 4/3 -9/4 = (16 -27)/12
x + y = -11/12

The appropriate choice is ..
c. -11/12

5 0

3 years ago

(f/g)(x)and (f/g)(7)

Phoenix [80]

Answer:

$(\frac{f}{g})(x)=\frac{f(x)}{g(x)}\\\\(\frac{f}{g})(7)=\frac{f(7)}{g(7)}$

Step-by-step explanation:

Division operation of function: $If\ f(x)\ and\ g(x)\ are\ two\ functions\ then\ (\frac{f}{g})(x)=\frac{f(x)}{g(x)}$

$Here\ we\ have\ to\ find\ (\frac{f}{g})(7)\\\\(\frac{f}{g})(7)=\frac{f(7)}{g(7)}$

Example:

$Take\ f(x)=3x^2+1,\ g(x)=x+1\\\\(\frac{f}{g})(x)=\frac{f(x)}{g(x)}\\\\(\frac{f}{g})(x)=\frac{3x^2+1}{x+1}\\\\f(7)=3\times 7^2+1\\\\f(7)=3\times 49+1\\\\f(7)=148\\\\g(7)=7+1\\\\g(7)=8\\\\(\frac{f}{g})(7)=\frac{f(7)}{g(7)}\\\\(\frac{f}{g})(x)=\frac{148}{8}$

7 0

3 years ago