Объяснение:
3. 7x²-6x+c=0
a) D=b²-4ac; 0=6²-4·7c; 0=36-4·7c; 7c=36/4; c=9/7=1 2/7
b) D=0; x₁=(6-√0)/14=3/7; x₂=(6+√0)/14=3/7
4. x²+6x+8=0
x₁+x₂=-6; -2+(-4)=-6
x₁·x₂=8; -2·(-4)=8
x₁=-2; x₂=-4
x₁²+x₂²x₁²+x₂²=4+16·4+16=20+64=84
5. a) x²-10x+24=x²-2·x·5+5²-1=(x-5)²-1
b) ax²+bx+c=a(x-x₁)(x-x₂)
x²-10x+24=0
x₁+x₂=10; 4+6=10
x₁·x₂=24; 4·6=24
x₁=4; x₂=6
x²-10x+24=(x-4)(x-6)
Объяснение:
3. 7x²-6x+c=0
a) D=b²-4ac; 0=6²-4·7c; 0=36-4·7c; 7c=36/4; c=9/7=1 2/7
b) D=0; x₁=(6-√0)/14=3/7; x₂=(6+√0)/14=3/7
4. x²+6x+8=0
x₁+x₂=-6; -2+(-4)=-6
x₁·x₂=8; -2·(-4)=8
x₁=-2; x₂=-4
x₁²+x₂²x₁²+x₂²=4+16·4+16=20+64=84
5. a) x²-10x+24=x²-2·x·5+5²-1=(x-5)²-1
b) ax²+bx+c=a(x-x₁)(x-x₂)
x²-10x+24=0
x₁+x₂=10; 4+6=10
x₁·x₂=24; 4·6=24
x₁=4; x₂=6
x²-10x+24=(x-4)(x-6)