Question

13) Calcule as equações irracionais:
a) 3 - x = VX-1
9) V7x - 3 - 1 = x

Answer 1

Explicação passo-a-passo:

Kkaks gostei da foto

a) 3-x= √x-1

(3-x)²=x-1

9-6x+x²=x-1

x²-7x+10= 0

x1+x2= 7

x1.x2= 10

x1 = 2

x2= 5

Answer 2

Resposta:

a) $x'=5 \ e \ x"=2$

9) $x'=\frac{-1+21i}{2} \ e \ x"=\frac{-1-21i}{2}$

Explicação passo-a-passo:

$a) 3-x=\sqrt{x-1}\\(3-x)^2=x-1\\9-6x+x^2=x-1\\x^2-7x+10=0\\\\\Delta=(-7)^2-4*1*10\\\Delta=49-40\\\Delta=9\\x=\frac{7^+_-3}{2} =\\x'=5 \ e \ x"=2$

$9)\sqrt{7x}-3-1=x\\\sqrt{7x}-4=x\\\sqrt{7x}=x+4\\(\sqrt{7x})^2}=(x+4)^2\\7x=x^2+8x+16\\x^2+x+16=0\\\\\Delta=1^2-4*1*16\\\Delta=1-64\\\Delta=-63\\\\x=\frac{-1^+_-\sqrt{-63}}{2}=\\x'=\frac{-1+21i}{2}  \ e \ x"=\frac{-1-21i}{2}$