Answer:
Option A is correct
Step-by-step explanation:
We have been given four equations and we need to tell which one of them is quadratic
Case1:
[tex]6(x+2)^2+8(x+2)+1[/tex]
In this we will use the formula [tex](a+b)^2=a^2+b^2+2ab[/tex]
Here, a=x and b=2
The equation will become [tex]6(x^2+2^2+4x)+8x+16+1[/tex]
Hence, after simplification equation will become
[tex]6x^2+24+24x+8x+16+1[/tex]
[tex]6x^2+32x+41[/tex] which is a quadratic equation because quadratic equation is the equation is the equation which has degree 2.
In this equation degree is 2 hence, quadratic
Case2:
[tex]6x^4+7x^2-3[/tex] is not quadratic since, degree in this equation is 4 not 2
Hence, biquadratic not quadratic
Case3:
[tex]5x^6+x^4+12[/tex] is not a quadratic equation since, degree in this equation is 6.
Hence, not quadratic
Case4:
[tex]x^9+x^3-10[/tex] is not quadratic since, degree in this equation is 9
Hence, not quadratic
Therefore, Option A is correct
