Solve x2-4x-7=0 by completing the square

Mathematics

2 answers:

aleksklad [387]3 years ago

8 0

HEY mate here is pratyush from India for your help...

the answer is with the attachment

hope it helps you..

tatyana61 [14]3 years ago

7 0

Answer:

x = 2 ± $\sqrt11}$

Step-by-step explanation:

Given

x² - 4x - 7 = 0 ( add 7 to both sides )

x² - 4x = 7

To complete the square

add (half the coefficient of the x- term)² to both sides

x² + 2(- 2)x + (- 2)² = 7 + (- 2)²

(x - 2)² = 7 + 4 = 11 ( take the square root of both sides )

x - 2 = ± $\sqrt{11}$ ( add 2 to both sides )

x = 2 ± $\sqrt{11}$ ← exact solutions

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