SOLUTION: Please help me solve this by COMPLETING THE SQUARE 28x-2x^2=26 I got no real solution. This is what I did, please correct me. -2x^2+28x=26 (28/2)^2=196 -2x^2+28x+196=26+19

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Please help me solve this by COMPLETING THE SQUARE 28x-2x^2=26 I got no real solution. This is what I did, please correct me. -2x^2+28x=26 (28/2)^2=196 -2x^2+28x+196=26+19      Log On


   



Question 1076100: Please help me solve this by COMPLETING THE SQUARE
28x-2x^2=26
I got no real solution. This is what I did, please correct me.
-2x^2+28x=26
(28/2)^2=196
-2x^2+28x+196=26+196
since you cannot take the square root of a negative, i got no real solution

√-2x^2 = no real solutions
Please help me, I am very confused. Thank you in advance, Emily

Found 4 solutions by Alan3354, josgarithmetic, MathLover1, MathTherapy:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
-2x^2+28x=26
(28/2)^2=196 **** Should be (b/2a)^2 = 49
-2x^2+28x+196=26+196
since you cannot take the square root of a negative, i got no real solution

√-2x^2 = no real solutions
=================
-2x^2+28x=26
I would start with this:
Divide by -2
x^2 - 14x = -13
Make it easier.

Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
-2x%5E2%2B28x-26=0

x%5E2-14x%2B13=0-----which is easily factorable...


Term which completes the square is %2814%2F2%29%5E2=49.

x%5E2-14x%2B49%2B13-49=0

%28x-7%29%5E2%2B13-49=0

%28x-7%29%5E2-36=0, standard form


SOLVE
%28x-7%29%5E2=36
x-7=0%2B-+6
x=7%2B-+6

-
system%28x=1%2COR%2Cx=13%29
which you would have also found through factoring earlier.

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

28x-2x%5E2=26+.....move all terms from the left to the right
0=2x%5E2-28x%2B26+..........group
0=%282x%5E2-28x%29%2B26+.....factor out 2
0=2%28x%5E2-14x%29%2B26+.........recall %28a%2Bb%29%5E2=a%5E2%2B2ab%2Bb%5E2; so, we need b part to complete our square
0=2%28x%5E2-14x%2Bb%5E2%29+-2%2Ab%5E2%2B26+........since a=1 and 2ab=14, we use it to calculate b
2ab=14=>2%2A1b=14=>b=14%2F2=>b=7
plug it in
0=2%28x%5E2-14x%2B7%5E2%29+-2%2A7%5E2%2B26+
0=2%28x-7%29%5E2-2%2A49%2B26+
0=2%28x-7%29%5E2-98%2B26+
0=2%28x-7%29%5E2+-72+

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Please help me solve this by COMPLETING THE SQUARE
28x-2x^2=26
I got no real solution. This is what I did, please correct me.
-2x^2+28x=26
(28/2)^2=196
-2x^2+28x+196=26+196
since you cannot take the square root of a negative, i got no real solution

√-2x^2 = no real solutions
Please help me, I am very confused. Thank you in advance, Emily
First of all, you're INCORRECT. You should see that after FACTORING OUT a GCF,  2, you'll end up with y+=+x%5E2+-+14x+%2B+13.
This can be FACTORED to get roots/solutions/zeroes of x = 13, or x = 1.
From this, it's clear that these will be your solutions, and they are REAL.
You could have also used the DISCRIMINANT to see if it really has No real solutions. If you did. You'd see that it does have 2 REAL solutions.
Now that we know this, let's get to the solutions by COMPLETING the SQUARE.
28x+-+2x%5E2+=+26

x%5E2+-+14x+=+-+13 ------- Rearranging equation
x%5E2+-+14x+%2B+%28%281%2F2%29+%2A+-+14%29%5E2+=+-+13+%2B+%28%281%2F2%29+%2A+-+14%29%5E2 -------- Taking matrix%281%2C3%2C+1%2F2%2C+of%2C+b%29, squaring it, and adding the result to both sides
x%5E2+-+14x+%2B+%28-+7%29%5E2+=+-+13+%2B+%28-+7%29%5E2
%28x+-+7%29%5E2+=+-+13+%2B+49
%28x+-+7%29%5E2+=+36
sqrt%28%28x+-+7%29%5E2%29+=+%22+%22%2B-+sqrt%2836%29 ------ Taking the square root of both sides
x+-+7+=+%22+%22%2B-+6 ======> x+=+%22+%22%2B-+6+%2B+7