Question

Rezolvați ecuația: x+y=14 x²-y²=56​

Answer 1

stim din formula ca a^2 -b-2 = (a-b)(a+b)

x^2-y^2= (x-y)(x+y)

56=(x-y)×14

x-y = 56:14

x-y=4

Answer 2

x+y=14 => x=14-y
=> (14-y)^2-y^2=56 => 14^2-2*14*y+y^2-y^2=56 => 196-28y=56 => 28y=196-56=140 => y=140:28 => y=5 => x=14-y=14-5 => x=9