Question

As raízes da equação x² - 7x + 10= 0, são :

a) 5 e 2

b) 10 e 4

c) 7 e 1

d) 6 e 1 ​

Answer 1

$\large\boxed{\begin{array}{lr}x {}^{2} - 7x + 10 = 0 \\ \\ a = 1 \\ b = - 7 \\ c = 10 \\ \\∆ = b {}^{2} - 4.a.c \\∆ = ( - 7) {}^{2} - 4.1.10 \\ ∆ = 49 - 40 \\∆ = 9 \\ \\ x = \frac{ - b \pm \sqrt{∆} }{2.a} \\ \\ x = \frac{ - ( - 7) \pm \sqrt{9} }{2.1} \\ \\ x = \frac{7 \pm3}{2} \\ \\ x_{1} = \frac{7 + 3}{2} = \frac{10}{2} = \boxed{5} \\ \\ x_{2} = \frac{7 - 3}{2} = \frac{4}{2} = \boxed{2} \\ \\ \boxed{S=\left\{ 5~,~2\right\}}\end{array}}$

$\large\boxed{\begin{array}{lr} \boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{ \huge\blue{opc_{\!\!,}\tilde{ao}~(A)~5~e~2}}}}}}}}}}}\end{array}}$

Answer 2

Resposta:

A)

Explicação passo a passo:

As raízes da equação:

x² - 7x + 10= 0

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

/\= b^2 - 4ac

/\= (-7)^2 - 4.1.10

/\= 49 - 40

/\= 9

X = [- b +/- \/ /\]/2a

X = [-(-7) +/- \/9] / 2.1

X = (7 +/- 3)/2

X' = (7+3)/2= 10/2= 5

X" = (7-3)/2= 4/2= 2

R.:

a) 5 e 2