Question

Решите уравнение x²+2x-7=0
2x²-4x-1=0
x²+6x+3=0
2x²-10x+1=0

Answer 1

x²+2x-7=0
D=2²-4*(-7)=4+28=32
√D=√32=4√2
x=(-2+4√2)/2=2√2-1
x=(-2-4√2)/2=-1-2√2

2x²-4x-1=0
D=4²-4*2*(-1)=16+8=24
√D=√24=2√6
x=(4+2√6)/2*2=1+√6/2
x=1-√6/2

x²+6x+3=0
D=6²-4*3=36-12=24
√D=√24=2√6
x=(-6+2√6)/2=√6-3
x=(-6-2√6)/2=-3-√6

2x²-10x+1=0
D=10²-4*2=100-8=92
√D=√92=2√23
x=(10+2√23)/2*2=(5+√23)/2
x=(5-√23)/2