Question

Pls ans:18 and 19 th Question i want step by step explanation​

Answer 1

Solution:

√(x² - 9 x + 18) + √(x² + 2 x - 15) = √(x² - 4 x + 3)

For removing the square root on left side first we have to take square on both sides

[√(x² - 9 x + 18) + √(x² + 2 x - 15)]² = [√(x² - 4 x + 3)]²

[√(x²-9x+18)]²+[√(x²+2x-15)]²+2√(x²-9x+18)(x²+2x-15)= (x²-4x+3)

x²-9x+18+x²+2x-15 + 2 √(x²-9x+18)(x²+2x-15) = (x²-4x+3)

2 x²-7 x + 3 + 2√(x²-9x+18)(x²+2x-15) = x²-4x+3

2√(x²-9x+18)(x²+2x-15) = x² - 4 x + 3 - 2 x² + 7 x - 3

2√(x²-9x+18)(x²+2x-15) = - x² + 3 x

now we are going to take squares on both sides

[2√(x²-9x+18)(x²+2x-15)]² = [- x² + 3 x]²

4(x²-9x+18)(x²+2x-15) = x⁴ + 2 (-x²)(3 x) + (3 x)²

4[x⁴+2x³-15x²-9x³-18x²+135x+18x²+36x-270] = x⁴ - 6 x³ + 9x²

4 [x⁴ - 7x³ -15 x² + 171 x - 270] = x⁴ - 6 x³ + 9x²

4x⁴ - 28 x³ -60 x² + 684 x - 1080 = x⁴ - 6 x³ + 9x²

4x⁴ - x⁴ - 28 x³ + 6 x³ - 60 x² - 9x²+ 684 x - 1080 = 0

3 x⁴ - 22 x³ - 69 x² + 684 x - 1080 = 0

Answer 2

19. Answer is above mentioned.