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mckayla_04
 3 years ago
Solve x2 + 9x + 9 = 0?
Quadratic Formulas
mckayla_04
 3 years ago
Solve x2 + 9x + 9 = 0? Quadratic Formulas

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jamesm
 3 years ago
Best ResponseYou've already chosen the best response.0quadratic formula: x = (9 + sqrt(45))/2 = (9 + 3*sqrt(5))/2 = 3(3 + sqrt(5))/2

Rohangrr
 3 years ago
Best ResponseYou've already chosen the best response.2here's a Example Solve the equation: x2  9x + 20 = 0 Solution First, factorise the quadratic equation x2 9x + 20 = 0 Find two numbers which add up to 9 and multiply to give 20. These numbers are 4 and 5. (x  4) (x  5) = 0 Now find the value x so that when these brackets are multiplied together the answer is 0. This means either (x  4) = 0 or (x  5) = 0 So x = 4 or x = 5. You can check these answers by substitutuing 4 and 5 in to the equation: x2 9x + 20 Substituting 4 gives: 42  9 × 4 + 20 = 16  36 + 20 = 0 Substituting 5 gives: 52  9 × 5 + 20 = 25  45 + 20 = 0 Remember these 3 simple steps and you will be able to solve quadratic equations. quadratic formula: x = (9 + sqrt(45))/2 = (9 + 3*sqrt(5))/2 = 3(3 + sqrt(5))/2

Rohangrr
 3 years ago
Best ResponseYou've already chosen the best response.2it will help u more than the solution

mckayla_04
 3 years ago
Best ResponseYou've already chosen the best response.0okay.. then what about 2x2 – 8x = –7?

lgbasallote
 3 years ago
Best ResponseYou've already chosen the best response.0just use what you have learned from their statements...the form of a quadratic equation is ax^2 + bx + c = 0 the quad formula is: x = b + sqrt (b^2  4(a)(c) ) all over 2a try :DD

Rohangrr
 3 years ago
Best ResponseYou've already chosen the best response.22x^2  8x + 7 = 0 (x  1) x (2x  7) = 0 You get an F if you can't finish it from here. Late edit: 8x. Crap use the equation to solve. ok. 2X^2  8X + 7 = 0 2(X^2  4X) + 7 = 0 2(X^2  4X + 4)  8 + 7 = 0 2(X2)^2  1 = 0 (X2)^2 = 1/2 X  2 = sqrt(1/2) X = 2 + sqrt(1/2) Or X = sqrt 2 x (sqrt 2 + 1) Or X = (4 + sqrt 2)/2.........your pref.
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