Answer:
a) x = 3
b)x = 1,-9
Step-by-step explanation:
given,
a)√(x²-5) = 2.................(1)
squaring both side in equation 1
(√(x²-5))² = 2²
x² - 5 = 4
x² = 9
x = 3
b) √(x²+8x)=3 .........................(2)
squaring both side in equation 2
(√(x²+8x))² = 3²
x²+8 x = 9
x²+8 x - 9 = 0
x² + 9 x - x - 9 = 0
x(x + 9) -1 (x + 9) = 0
( x - 1)(x + 9) = 0
x = 1,-9
