Решите уравнение 2(5x-7)(1+x)= 0
2(5x-7)(1+x)= 0
(10x-14)(1+x)=0
10x+10x²-14-14x=0
10x²-4x-14=0
x²-2/5x-7/5=0
1/5±√1/25+7/5
x₁=1/5+6/5=7/5
x₂=1/5-6/5=-1