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Susu is solving the quadratic equation 4x2 – 8x – 13 = 0 by completing the square. Her first four steps are shown in the table. In which step did Susu first make an error? Step 1 Step 2 Step 3 Step 4

Susu is solving the quadratic equation 4x2 – 8x – 13 = 0 by completing the square-example-1
User Rightparen
by
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2 Answers

1 vote

Answer:

Step 3

Explanation:

when solving by completing the square you are supposed to do (b/2)^2 and then add that to both sides.

In your example (-8/2)^2=16

You are supposed to add sixteen to both sides not 64

Susu forgot to divide 8 by 2 before she raised it to the to the second powerm that is why she got 64, which is incorrect.

User Centurian
by
7.5k points
3 votes

Answer:

Step 2

Explanation:

Susu is solving the quadratic equation
4x^2 - 8x - 13 = 0 by completing the square

To apply completing the square method we need to get x^2 alone

Susu added 13 on both sides . So step 1 is correct

When we factor out 4, we divide both terms by 4


4((4x^2)/(4) -(8x)/(2) )=13


4(x^2-2x)=13

Susu forgot to divide 8 by 4

So , error in step 2

User Heena Arora
by
7.2k points
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