Quadratic EquationsDate: 6/25/96 at 18:36:45 From: Sandi Pohlmann Subject: Quadratic Equations Use the zero-factor property to solve. (2a-5)(a+3) = 0. z(z-7) = 0. Solve each equation by the square root property. p^2 = 16. Solve each equation by using the quadratic formula. q2 - 7q + 6 = 0. Thank you. Date: 6/26/96 at 10:4:34 From: Doctor Jerry Subject: Re: Quadratic Equations 1. This is in the form of a product of two numbers. The zero-factor property is the fact that if the product of two numbers is zero, then at least one of them must be zero. So, either 2a-5 = 0 or a+3 = 0. Solving these simpler equations gives a = 5/2 or a = -3. So, if a is either of these values, the equation is satisfied. 2. Using the same property, z = 0 or z = 7. 3. So, if p^2 = 16, then p is a number whose square is 16. Thus p must be either 4 or -4, which are the square roots of 16. 4. For ax^2 + bx + c = 0, the quadratic formula is -b +- sqrt(b^2-4ac) ------------------ 2a The sign +- means plus or minus. Just substitute, a = 1, b = -7, and c = 6. This gives -(-7) +- sqrt[49-4(1)(6)] ------------------------- . (2) This simplies to 7 +- sqrt(25) or (7+5)/2 and (7-5)/2 or 6 and 1. -------------- 2 Good luck. -Doctor Jerry, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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