Question

1)x^2+9x+14=0 2)2x^2-23x+65=0 3)2x^2-27x+88=0 4)x^2-5x+6=0 5)x^2-14x+49=0 6)x^2-9x+14=0 7)x^2+4x=0 8)3x^2-9=0 9)4x^2-8=0 10)x^2-6x=0

Answer 1

5. D=(-14)^2-4×1×49=0

x1,x2= 7

6. D=(-9)^2-4×1×14=25

x1=7 x2= 2

7. x(x+4)=0

x=0 x=-4

8. 3(x^2-3)=0

x=+-√3

9. 4(x^2-2)=0

x=+-√2

10. x(x-6)=0

x=0 x=6