Question

Entre as raizes da equacao 3x²+18x+10=31

Answer 1

3x² + 18x + 10 = 31

3x² + 18x + 10 - 31= 0

3x² + 18x - 21 = 0 (:3)

x² + 6x - 7 = 0

Δ = 6² - 4.1.(-7)

Δ = 36 + 28

Δ = 64

x = - 6 +-√64/2

x' = - 6 + 8/2 = 2/2 = 1

x" = - 6 - 8/2 = - 14/2 = - 7

Answer 2

$3 {x}^{2} + 18x + 10 - 31 = 0 \\ (3 {x}^{2} + 18x - 21) \div 3 = 0 \div 3 \\ {x}^{2} + 6x - 7 = 0 \\ \\ formula \: de \: baskara \\ \\ \frac{ - 6 (+ -) \sqrt{ {6}^{2} - 4 \times 1 \times ( - 7)} }{2 \times 1} = \\ = - (6( + - )8) \div 2 = 1 \: ou \: -7$