Question

caucule a soma eo produto das raises das equaçoes:

a)x²-7x10=0

b)2x²-10x-12=0

c)8x²-7=0

d)1+12x=9x²

Answer 1

A= x²-7x10=0
x²-70= 0
x²=70
x=√70
x=-√70
S={√70,-√70}

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B= 2x²-10x-12=0

a=2 b=10 c=12


∆=(-10)²-4.2.(-12)
∆=100+(-8).(-12)
∆=100+96
∆=196

X1=-(-10)+√196/2.2
X1=10+√196/4
X1=10+14/4
X1=24/4
X1=6


x2=-(-10)-√196/2.2
x2=10-√196/4
x2=10-14/4
x2=-4/4
x2=-1
S={6,-1}

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C= 8x²-7=0
8x²=7
x²=7/8
x= +√14/4
x= -√14/4
S={√14/4, -√14/4}

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D= 1+12x=9x²
1+12x-9x²=0
-9x²+12x+1=0
a=-9 b=12 c=1

∆=(12)²-4.(-9).1
∆=144+36
∆=180

X1= -(12)+√180/(2.-9)
x1= -12+13,4164/-18
X1= 1,4164/-18
X1=0,0787

x2=-(12)-√180/(2.-9)
x2= -12-13,4164/-18
x2=-25,4164/-18
x2=1,412

S={0,0787 , 1,412}


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