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Determine the roots of the equation x^2+2x-5=0

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3 Answers

x^2 + 2x - 5 is equivalent to ax^2 + bx + c, that's why a= 1, b= 2, c= -5 Like others said earlier, u would use quadratic eq. -b±v(b2-4ac) is numerator 2a is denominator Therefore, -2 ±v (2^2 - 4*1*-5) = -2 ±v(4+20) = -2 ±v24 = -2 ± 2v6 v6 = 2.45 2v6 = 4.90 -2 - 4.90 = -6.90 -2 + 4.90 = 2.90 denominator is just "2" so divide numerator by "2" to get answer. Answer is x= 1.45 or -3.45 try plugging in these values for x into equation to confirm accuracy. For example, 1.45^2 + 2*1.45 - 5 = 0? -3.45^2 + 2*-3.45 - 5 = 0?

x= 2.9 x= -6.9

use -the quadratic equation to solve -b+ (the square root of b - 4ac) /(2a)

substitute the numbers from the given equation into this equation and solve.

b=2 , a=1 c= -5