Answer :
x² + (3x - 9)² = (2x + 1)²
x² + (3x - 9)(3x - 9) = (2x + 1)(2x + 1)
x² + (9x² - 27x - 27x + 81) = (4x² + 2x + 2x + 1)
x² + (9x² - 54x + 81) = 4x² + 4x + 1
(x² + 9x²) - 54x + 81 = 4x² + 4x + 1
10x² - 54x + 81 = 4x² + 4x + 1
- 4x² - 4x²
6x² - 54x + 81 = 4x + 1
+ 54x + 54x
6x² + 81 = 58x + 1
- 1 - 1
6x² + 80 = 58x
6x² - 58x + 80 = 0
x = -(-58) +/-√((-58)² - 4(6)(80)
2(6)
x = 58 +/- √(3364 - 1920)
12
x = 58 +/- √(1444)
12
x = 58 +/- 38
12
x = 58 + 38 x = 58 - 38
12 12
x = 96 x = 20
12 12
x = 6 x ≈ 1.67
x² + (3x - 9)(3x - 9) = (2x + 1)(2x + 1)
x² + (9x² - 27x - 27x + 81) = (4x² + 2x + 2x + 1)
x² + (9x² - 54x + 81) = 4x² + 4x + 1
(x² + 9x²) - 54x + 81 = 4x² + 4x + 1
10x² - 54x + 81 = 4x² + 4x + 1
- 4x² - 4x²
6x² - 54x + 81 = 4x + 1
+ 54x + 54x
6x² + 81 = 58x + 1
- 1 - 1
6x² + 80 = 58x
6x² - 58x + 80 = 0
x = -(-58) +/-√((-58)² - 4(6)(80)
2(6)
x = 58 +/- √(3364 - 1920)
12
x = 58 +/- √(1444)
12
x = 58 +/- 38
12
x = 58 + 38 x = 58 - 38
12 12
x = 96 x = 20
12 12
x = 6 x ≈ 1.67
