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22 votes
22 votes
What is the sum
of the solutions to
x² - 7 = 6x?

User Micans
by
3.2k points

1 Answer

18 votes
18 votes

Explanation:

x² - 7 = 6x

x² - 6x - 7 = 0

the generation solution to such a quadratic ratatouille

ax² + bx + c = 0

is

x = (-b ± sqrt(b² - 4ac))/(2a) =

= (6 ± sqrt((-6)² - 4×1×-7))/(2×1) =

= (6 ± sqrt(36 + 28))/2 = (6 ± sqrt(64))/2 =

= (6 ± 8)/2 = (3 ± 4)

x1 = 3 + 4 = 7

x2 = 3 - 4 = -1

the sum of both solutions is : 7 + -1 = 7 - 1 = 6

User John Kline Kurtz
by
3.1k points