Question

com a forma resolutiva resolva as seguintes equações.

Answer 1

A) 2x²+7x+5
a=2
b=7
c=5

$x=\frac{-b+-\sqrt{xlb^{2}-4ac}}{2a}$

$x= \frac{-7+-\sqrt{7^{2}-4.2.5}}{2.2}$

$x= \frac{-7+-\sqrt{49-40}}{4}$

$x= \frac{-7+-\sqrt{9}}{4} = \frac{-7+-3}{4}$

x'= (-7+3)/4= -1
x"= (-7-3)/4= -2,5

B) x²+5x-14=0
a=1
b= 5
c= -14

$x= \frac{-5+-\sqrt{5^{2}-4.1.(-14)}}{2.1}$

$x= \frac{5+-\sqrt{25+56}}{2} = \frac{5+-\sqrt{81}}{2} = \frac{5+-9}{2}$

x'=(5+9)/2=7
x"=(5-9)/2= -2

C) x²-6x+9=0
a=1
b= -6
c=9

$x= \frac{-(-6)+-\sqrt{(-6^{2})-4.1.9}}{2.1}$

$x= \frac{6+-\sqrt{36-36}}{2} = \frac{6+-\sqrt{0}}{2} = \frac{6}{2}$

x'=x"= 6/2=3

D) -x²+8x+9=0
a= -1
b=8
c=9

$x=\frac{-8+-\sqrt{8^{2}-4.(-1).9}}{2.(-1)}$

$x= \frac{-8+-\sqrt{64+36}}{-2}$

$x= \frac{-8+-\sqrt{100}}{-2} = \frac{-8+-10}{-2}$

x'= (-8+10)/-2= -1
x"= (-8-10)/-2= 9

Espero ter ajudado!