Expand 1/x^2-4 using partial fraction decomposition

1 / X² -4 = (- 1/4) / (X+2) + (1/4) / (X - 2)

Step-by-step explanation:

1 / x²-4 = 1 / (X+2) * (X-2)

1 / X²-4 = (A / X+2) + (B / X-2) = (AX - 2A + BX +2B) / X² -4

∴ 1 = (A + B) * X - 2 (A - B)

A + B = 0

- 2 (A - B) = 1

A - B = - 1/2

∴ 2A = - 1/2

A= - 1/4

B= 1/4

1 / X² -4 = (- 1/4) / (X+2) + (1/4) / (X - 2)

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option