SOLUTION: Find the value of y in the quadratic equation y^2 +4y +4 =7

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Question 271993: Find the value of y in the quadratic equation
y^2 +4y +4 =7
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
y%5E2+%2B4y+%2B4+=7
Solving quadratic equations start with getting one side of the equation equal to zero. So we'll subtract 7 from each side:
y%5E2+%2B+4y+-3+=+0
Next we would either factor the non-zero side or use the Quadratic Formula. Normally I prefer factoring but this equation does not factor. So we must use the Quadratic Formula, x+=+%28-b+%2B-+sqrt%28b%5E2+-+4ac%29%29%2F%282a%29. Using this on our equation we get:
y+=+%28-%284%29+%2B-+sqrt%28%284%29%5E2+-+4%281%29%28-3%29%29%29%2F%282%281%29%29
Simplifying we get:
y+=+%28-4+%2B-+sqrt%2816+-+4%281%29%28-3%29%29%29%2F2
y+=+%28-4+%2B-+sqrt%2816+%2B+12%29%29%2F2
y+=+%28-4+%2B-+sqrt%2828%29%29%2F2
y+=+%28-4+%2B-+sqrt%284%2A7%29%29%2F2
y+=+%28-4+%2B-+sqrt%284%29%2Asqrt%287%29%29%2F2
y+=+%28-4+%2B-+2%2Asqrt%287%29%29%2F2
y+=+%282%28-2+%2B-+sqrt%287%29%29%29%2F2
y+=+%28cross%282%29%28-2+%2B-+sqrt%287%29%29%29%2Fcross%282%29
y+=+-2+%2B-+sqrt%287%29