Question

gente pelo amor de Deus preciso muito da ajuda de voocs :( ', 

    

 

  calcule essas equações de 2 grau : 

 

  1° x²+3x-10=0 

  2° x²+2x+1=0

  3° x²+6x-7=0

  4° x²-2x-8=0

  5° 2x²-9x+4=0

  6° x²-2x=x+4

  7° 25x²-10x+1=0

  8°x²+10=9x-10

  9° x²-2x-15=0

10° (x+2)²+x=0

Answer 1

1)x²+3x-10=0
a=1 b=3 c=-10
delta=b²-4.a.c
delta=3²-4.1.(-10)
delta=9-4.(-10)
delta=9+40
delta=49

$\frac{-b+- \sqrt{delta}}{2.a}$

$\frac{-3+- \sqrt{4} }{2.1}$

$\frac{-3+-7}{2}$

x'=$\frac{-3+7}{2} = \frac{4}{2} :2= \frac{2}{1}$

x''=$\frac{-3-7}{2}= \frac{-10}{2}$

2)x²+2x+1=0
a=1 b=2 c=1
delta=b²-4.a.c
delta=2²-4.1.1
delta=4-4
delta=0

$\frac{-b+- \sqrt{delta} }{2.a}$

$\frac{-2+- \sqrt{0} }{2.1}$

$\frac{-2}{2} :2= 1$


3) x²+6x-7=0
a=1 b=6 c=-7
delta=b²-4.a.c
delta=6²-4.1.(-7)
delta=36-4.(-7)
delta=36-11
delta=25

$\frac{-b+- \sqrt{delta} }{2.a}$ = $\frac{-6+- \sqrt{25} }{2.1}$

$\frac{-6+-5}{2}$

x'=$\frac{-6-5}{2} = \frac{-11}{2}$

x''=$\frac{-6+5}{2} = \frac{-1}{2}$

4) x²-2x-8=0
a=1 b=-2 c=-8
delta=b²-4.a.c
delta=(-2)²-4.1.(-8)
delta=4-4.(-8)
delta=4-(-32)
delta=4+32=36

$\frac{-b+- \sqrt{delta} }{2.1} = \frac{-(-2)+- \sqrt{36} }{2}$

$\frac{2+-6}{2}$

x'=$\frac{2+6}{2} = \frac{8}{2} :2 = \frac{4}{1}$

x''=$\frac{2-6}{2}= \frac{-4}{2}$

5) 2x²-9x+4=0
a=2 b=-9 c=4
delta=b²-4.a.c
delta=(-9)²-4.2.4
delta=81-32
delta=49

$\frac{-b+- \sqrt{delta} }{2.a} = \frac{-(-2)+- \sqrt{49} }{2.2}$

$\frac{2+-7}{4}$

x'= $\frac{2+7}{4}= \frac{9}{4}$
x''$\frac{2-7}{4} = \frac{-5}{4}$