Home
Class 14
MATHS
If 5(3x+4)-8(6x+7)=9x-8, then what is th...

If `5(3x+4)-8(6x+7)=9x-8`, then what is the value of `(x^2-2x+1)?`

A

`2/3`

B

`4/9`

C

`5/3`

D

`25/9`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \( 5(3x + 4) - 8(6x + 7) = 9x - 8 \), we will follow these steps: ### Step 1: Distribute the terms on the left side We start by distributing the \(5\) and \(-8\) across the parentheses: \[ 5(3x + 4) = 15x + 20 \] \[ -8(6x + 7) = -48x - 56 \] ### Step 2: Combine the distributed terms Now we combine the results from Step 1: \[ 15x + 20 - 48x - 56 = 9x - 8 \] Combine like terms on the left side: \[ (15x - 48x) + (20 - 56) = 9x - 8 \] \[ -33x - 36 = 9x - 8 \] ### Step 3: Move all terms involving \(x\) to one side Next, we will add \(33x\) to both sides of the equation: \[ -36 = 9x + 33x - 8 \] \[ -36 = 42x - 8 \] ### Step 4: Isolate the \(x\) term Now, we will add \(8\) to both sides: \[ -36 + 8 = 42x \] \[ -28 = 42x \] ### Step 5: Solve for \(x\) Now, we divide both sides by \(42\): \[ x = \frac{-28}{42} \] Simplifying this fraction gives: \[ x = \frac{-2}{3} \] ### Step 6: Substitute \(x\) into the expression \(x^2 - 2x + 1\) Now we need to find the value of \(x^2 - 2x + 1\): \[ x^2 - 2x + 1 = \left(\frac{-2}{3}\right)^2 - 2\left(\frac{-2}{3}\right) + 1 \] Calculating each term: \[ \left(\frac{-2}{3}\right)^2 = \frac{4}{9} \] \[ -2\left(\frac{-2}{3}\right) = \frac{4}{3} = \frac{12}{9} \] \[ 1 = \frac{9}{9} \] Now, combine these results: \[ x^2 - 2x + 1 = \frac{4}{9} + \frac{12}{9} + \frac{9}{9} = \frac{4 + 12 + 9}{9} = \frac{25}{9} \] ### Final Answer Thus, the value of \(x^2 - 2x + 1\) is: \[ \frac{25}{9} \] ---
Promotional Banner