Question

solve: x^2-4x-7=0 and give your answer correct to 3 significant figures​

Answer 1

Answer:

answer for the equation is. 2+root11 and 2-root11

Answer 2

Step-by-step explanation:

${x}^{2} - 4x - 7 \\ compare \: equation \: with \: a {x}^{2} + bx + c = 0 \\ a = 1 \: \: \: \: \: b = - 4 \: \: \: \: \: \: \: \: c = - 7 \\ {b}^{2} - 4ac = ( { - 4)}^{2} - 4 \times 1 \times ( - 7) \\ = 16 + 28 = 44 \\ using \: formula \\ x = \frac{ - b + - \sqrt{ {b}^{2} - 4ac} }{2a} \\ x = \frac{ - ( - 4) + - \sqrt{44} }{2} \\ x = \frac{4 + - \sqrt{44} }{2} \\ x = \frac{4 + - 2 \sqrt{11} }{2} \\ x = \frac{4 + 2 \sqrt{11} }{2} \: \: \: \: \: \: or \: \: \: \: \: x = \frac{4 - 2 \sqrt{11} }{2} \\ x = \frac{2(2 + \sqrt{11} )}{2} \: \: \: \: \: or \: \: \: \: \: x = \frac{2(2 - \sqrt{11} )}{2} \\ cancel \: \:out \: \: \: \: 2\\ x = 2 + \sqrt{11} \: \: \: \: \: or \: x = 2 - \sqrt{11}$

Hope it helps you

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Thanks for the question siso