SOLUTION: Please help me with my Algebra 2 math homework. I just need help on one question: how does one solve: x^2-13x+42=0 Here is what I have so far: Subtract 42 from both sides

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Question 406473: Please help me with my Algebra 2 math homework. I just need help on one question: how does one solve: x^2-13x+42=0

Here is what I have so far: Subtract 42 from both sides. Divide -13 by 2 and square -6.5 to get 42.25. Add 42.25 to both sides. Now my equation is
x^2-13x+42.25=0.25.
Now, how can I factor out the equation to solve it?
Thank you for your help!
Found 3 solutions by mananth, Alan3354, stanbon:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
x^2-13x+42=0

squaring method
x^2-13x+169/4 +42=+169/4
(x-13/2)^2= 169/4 -42
(x-13/2)^2= 1/4
Take the square root on both sides
(x-13/2) = +/- 1/2
..
x= 13/2 +1/2 = 7
OR
x=13/2 -1/2 =6

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
how does one solve: x^2-13x+42=0

Here is what I have so far: Subtract 42 from both sides. Divide -13 by 2 and square -6.5 to get 42.25. Add 42.25 to both sides. Now my equation is
x^2-13x+42.25=0.25
Now, how can I factor out the equation to solve it?
----------------
%28x+-+6.5%29%5E2+=+0.5%5E2
x - 6.5 = ± 0.5
x = 6, 7
-------------
x^2-13x+42=0
(x-6)*(x-7) = 0
x = 6, 7

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
solve:
x^2-13x+42=0
---
Think of two numbers whose product is 42
and whose sum = -13
-----
The numbers are -6 and -7
-----------------------------
Rewrite the equation replacing -13x by -6x-7x
-----
x^2-6x-7x+42 = 0
---
Factor:
x(x-6)-7(x-6) = 0
---
(x-6)(x-7) = 0
---
x = 6 or x = 7
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Cheers,
Stan H.
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