Question

а) (х – 5)(x+5) — х(х-3) = 5
б) х(х + 2) = (х – 3)(х+3) = 7

Answer 1

а)

$( x - 5)(x + 5) - x(x - 3) = 5 \\ {x}^{2} - 25 - {x}^{2} + 3x = 5 \\ 3x = 30 \\ x = 10$

б)

$x(x + 2) = (x - 3)(x + 3) = 7 \\ {x}^{2} + 2x = {x}^{2} - 9 = 7 \\ {x}^{2} + 2x - {x}^{2} = 7 + 9 \\ 2x = 16 \\ x = 8$