Question

4) ) Determine as raízes das seguintes equações: a) x2-4x+3=0 b) x2-7x+10=0​

Answer 1

Resposta:

a) x²-4x+3=0

a = 1 / b = -4 / c = 3

Δ = ( - 4)² - 4 . 1 . 3

Δ = 16 - 12

Δ = 4  → √Δ = 2

As raizes:

$x' = \frac{- ( - 4 ) + 2 }{2 . 1 } => x' = \frac{4+2}{2} => x' = \frac{6}{2}=>x'=3 \\\\x'' = \frac{- ( - 4 ) - 2 }{2 . 1 } => x'' = \frac{4-2}{2} => x'' = \frac{2}{2}=> x''=2$

b) x²-7x+10=0

a = 1 / b = -7 / c = 10

Δ = ( - 7 )² - 4 . 1 . 10

Δ = 49 - 40

Δ = 9 → √Δ = 3

As raizes:

$x'=\frac{-(-7)+ 3}{2.1} => x'=\frac{7+3}{2} => x'=\frac{10}{2} => x'=5\\\\x'' =\frac{-(-7)- 3}{2.1} => x''=\frac{7-3}{2} => x''=\frac{4}{2} => x''=2$