Nicole C. answered • 10/03/12
Increase confidence in math and science, chemistry, algebra II
X2 - 2x-13=0 with the following steps:
1. Move the constant term to the right side of the equation.
x2 - 2x = 13
2. Multiply each term in the equation by four times the coefficeint of the x2 term.
The coefficient is originally 1, so 4(1) = 4
4(x2 - 2x = 13)
4x2 - 8x = 52
3. Square the coefficient of the original x term and add it to both sides of the equation.
The coefficient is originally 2, so (2)2 = 4
4x2 - 8x (+4)= 52 (+4)
4x2 - 8x + 4 = 56
4. Take the square root of both sides.
√(4x2 - 8x + 4) = √(56)
√4(x - 1)(x - 1) = √(4)(14)
2(x - 1) = 2√14
5. Set the left side of the equation equal to the positve square root of the number on the right side and solve for x.
2(x - 1) = 2√14 change 2√14 into a decimal
2(x - 1) = 7.48 divide both sides by 2
(x - 1) = 3.74 add 1 to both sides
x = 4.74
6. Set the left side of the equation equal to the negative square root of the number on the right side and solve for x.
2(x - 1) = - 7.48
(x - 1) = - 3.74
x = -2.74
7. Set the left side of the equation equal to the negative square root of the number on the right side of the equation and solve for x.
I think this is a repeat of #6
Nicole C.
Thanks for the feedback.
10/04/12
Pam K.
Great, thank you so much. I was stuck at step 3. I have several others to do, so this will help.
10/04/12