An algebra problem by A Former Brilliant Member

Algebra Level 2

Find constant A that make the equation true

2x-9/x^2- x- 6 = A/x-3 + B/x+2

NOTE:- If your answer is 3/4 write it as 0.75. If your answer is recurring, round it of to 2 decimal places.


The answer is -0.6.

A Former Brilliant Member by A Former Brilliant Member

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

This is fractional decomposition.

(2x - 9) = A(x + 2) + B(x - 3)

2x - 9 = Ax + 2A + Bx - 3B

2x - 9 = Ax + Bx + 2A - 3B

2x - 9 = x(A + B) + 2A - 3B

set up a system of equations

2 = A + B

-9 = 2A - 3B

A = 2 - B

-9 = 2(2 - B) - 3B

-9 = 4 - 2B - 3B

-9 = 4 - 5B

-13 = -5B

B = 13/5

A = -3/5

Therefore A = -0.6

1 Helpful 0 Interesting 0 Brilliant 0 Confused

Nice

Neo Xiu Yang - 7 years, 1 month ago

You really need to write in parentheses in the proper places! I certainly cannot decipher this problem as such.

tom engelsman - 8 months, 2 weeks ago

Is the question 2x-9/x^2- x- 6 = A/(x-3) + B/(x+2)...?

Shruthi Dev - 7 years ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...