Which of the following equations cannot be solved by completing the square?

Option B. x^2+4=9

Step-by-step explanation:

You can complete the square when the equation has the form:

ax^2+bx with "a" and "b" different of zero.

In equation A. x^2+4x=9; a=1 and b=4 are different of zero. We can solve the equation by completing the square.

In equation B. x^2+4=9. If we subtract 4 from both sides of the equation:

x^2+4-4=9-4→x^2=5; a=1 but b=0, then we cannot solve the equation by completing the square.

In equation C. x^2+3x=0; a=1 anb b=3 are different of zero. We can solve the equation by completing the square.

In equation D. x^2+4x=x+9

If we subtract x from both sides of the equation:

x^2+4x-x=x+9-x→x^2+3x=9; a=1 and b=3 are different of zero. We can solve the equation by completing the square.

answer: 193

explanation:

200-7 = 193