Determine Variables A, B, and C for the Equation: (A/X) + (BX/2) = ((2X+3)²)/X - C

Question

AX+BX2=(2X+3)2XC \frac{A}{X}+\frac{BX}{2}=\frac{(2X+3)^2}{X}-C

Calculate the values of A, B, and C so that the equation is satisfied.

Video Solution

Solution Steps

00:00 Find A,B,C
00:03 Multiply by the common denominator to eliminate fractions
00:44 Reduce what's possible
00:56 Use shortened multiplication formulas to open the parentheses
01:19 Move C to the left side
01:24 Calculate the squares and products
01:40 Open parentheses properly, multiply by each factor
01:50 Equate each coefficient on the right side to the coefficient on the left side
01:56 This is the solution for B
02:07 Factor 24 into factors 2 and 12
02:16 This is the solution for C
02:23 Factor 18 into factors 9 and 2
02:27 This is the solution for A
02:30 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we will simplify both sides of the given equation:

Given equation:

AX+BX2=(2X+3)2XC \frac{A}{X} + \frac{BX}{2} = \frac{(2X+3)^2}{X} - C .

First, expand the quadratic expression:

(2X+3)2=(2X+3)(2X+3)=4X2+6X+6X+9=4X2+12X+9 (2X+3)^2 = (2X+3)(2X+3) = 4X^2 + 6X + 6X + 9 = 4X^2 + 12X + 9 .

Substitute this back into the equation:

AX+BX2=4X2+12X+9XC \frac{A}{X} + \frac{BX}{2} = \frac{4X^2 + 12X + 9}{X} - C .

Simplify the right-hand side:

4X2+12X+9X=4X+12XX+9X=4X+12+9X \frac{4X^2 + 12X + 9}{X} = 4X + \frac{12X}{X} + \frac{9}{X} = 4X + 12 + \frac{9}{X} .

The equation now becomes:

AX+BX2=4X+12+9XC \frac{A}{X} + \frac{BX}{2} = 4X + 12 + \frac{9}{X} - C .

For the equation to hold true for all values of X X , equate corresponding terms:

  • AX=9XA=9 \frac{A}{X} = \frac{9}{X} \Rightarrow A = 9 .
  • BX2=4XB=8 \frac{BX}{2} = 4X \Rightarrow B = 8 .
  • For constant terms: 12C=0C=12 12 - C = 0 \Rightarrow C = 12 .

Therefore, the values are A=9 A = 9 , B=8 B = 8 , and C=12 C = 12 .

The correct answer is: A=9,B=8,C=12 A = 9, B = 8, C = 12 .

Answer

A=9,B=8,C=12 A=9,B=8,C=12