Question

найти сумму корней уравнения

Answer 1

D=6^2-4*1*(-7)=36+28=64; x1=(-6-8)/2, x2=(-6+8)/2. x1= -7, x2=1. x1+x2= -7+1= -6. Ответ: x1+x2= -6.

Answer 2

${x}^{2} + 6x - 7 = 0 \ {x}^{2} + 7x - x - 7 = 0 \ x(x + 7) - (x + 7) = 0 \x (x + 7) times (x - 1) = 0 \ x + 7 = 0 \ x - 1 = 0$
x1 = -7
x2 = 1
x1+ x2 = -7 + 1 = -6