Solve for x in the equation x² - 4x - 9 = 29.
Answer: First option.
Step-by-step explanation:
1. To solve this problem you can applly the quadratic formula, which is shown below:
[tex]x=\frac{-b+/-\sqrt{b^{2}-4ac}}{2a}[/tex]
2. The quadratic equation is:
[tex]x^{2}-4x-9-29=0\\x^{2}-4x-38=0[/tex]
3. Then:
a=1
b=-4
c=-38
4. Therefore, when you substitute these values into the quadratic formula, you obtain the following result:
[tex]x=\frac{-(-4)+/-\sqrt{(-4)^{2}-4(1)(-38)}}{2(1)}[/tex]
x=2±√42
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.