Question

Solve for x in the equation x² - 4x - 9 = 29.

Answer 1

Answer:

Choice a is correct answer.

Step-by-step explanation:

Given equation is :

x²-4x-9 = 29

Adding -29 to both sides of above equation , we get

x²-4x-9-29 = -29+29

x²-4x-38 = 0

ax²+bx+c = 0 is general quadratic equation .

Comparing given equation with quadratic equation , we get

a = 1 , b = -4 and c = -38

x = (-b±√b²-4ac) / 2a

Putting above values in quadratic equation, we get

x = ( -(-4) ± √(-4)²-4(1)(-38) ) / 2(1)

x = ( 4±√16+152) / 2

x = ( 4± √168) / 2

x = (4±√4×42) / 2

x = (4±2√42) / 2

taking 2 common, we get

x = 2( 2±√42) / 2

x  = 2±√42 which is the answer.

Answer 2

Answer: First option.

Step-by-step explanation:

 1. To solve this problem you can applly the quadratic formula, which is shown below:

 $x=\frac{-b+/-\sqrt{b^{2}-4ac}}{2a}$

2. The quadratic  equation is:

$x^{2}-4x-9-29=0\\x^{2}-4x-38=0$

3. Then:

a=1

b=-4

c=-38

4. Therefore, when you substitute these values into the quadratic formula, you obtain the following result:

$x=\frac{-(-4)+/-\sqrt{(-4)^{2}-4(1)(-38)}}{2(1)}$

x=2±√42