Question

Alguem ai sabe? pf pra amanhã à tarefa

Answer 1

c) x²-(x-1).(2x-2)=3x

$x^{2}-2x^{2}-2x-2x+2=3x \\ -x^{2}-4x+2=3x \\ -x^{2}-4x-3x+2=0 \\ -x^{2}-7x+2=0 \\ \\ b^{2}-4ac=(-7)^{2}-4.(-1).(2) = \\ b^{2}-4ac=49+8 = 57$

$x'= \frac{-b+ \sqrt{b^{2}-4ac}}{2a} = \frac{-(-7)+7,55}{2.(-1)} \\ \\ x' = \frac{14,55}{-2} = -7,28$

$x"= \frac{-b- \sqrt{b^{2}-4ac}}{2a} = \frac{-(-7)-7,55}{2.(-1)} \\ \\ x" = \frac{7,55}{-2} = -3,78$

d) $( \frac{x}{ \sqrt{3}})^{2} -5x=x-1$

$\\ x^{2}+3-5x-x+1=0 \\ x^{2}-6x+4=0 \\ \\ b^{2}-4ac = (-6)^{2}-4.1.4 \\ = 36-16 = 20$

$\\ x'= \frac{-b+ \sqrt{b^{2}-4ac}}{2a} = \frac{-(-6)+4,47}{2.1} = 5,24 \\ x"= \frac{-(-6)- \sqrt{b^{2}-4ac}}{2a} = \frac{-(-6)-4,47}{2.1} = 0,77$