Question

PRECISO URGENTE prova de matematica segunda feira

Answer 1

a) x²-25=0
x²=25
x= √25 = 5
b)2x²-98=0
2x²=98
x²=98/2
x²=49
x=√49 = 7
c)9x²=5x
9x²-5x=0
∆= (-5)²-4.9.0
∆= 25-0
∆=25
x=5±5/18
x'= 10/18(÷2) = 5/9
x"= 0/18 = 0
d)5x²=-10x
5x²+10x=0
∆= 10²-4.5.0
∆= 100-0
∆=100
x=-10±10/10
x'= 0/10 = 0
x"= -20/10 = -2
e)-x²+x+12=0
∆= 1²-4.-1.12
∆= 1+48
∆= 49
x= -1±7/-2
x'= 6/-2= -3
x"= -8/-2 = 4
f) 7x²+x+1=0
∆= 1²-4.7.1
∆= 1-28
∆= -27
equação sem solução
g)(x-2)²-x=1
x²-4x+4-x-1=0
x²-5x+3=0
∆= (-5)²-4.1.3
∆= 25-12
∆= 13
x= 5±√13/2
x'= 5+√13/2
x"= 5-√13/2
h) x²= 4/5x+1/5 (.5)
5x²-4x-1=0
∆= (-4)²-4.5.-1
∆= 16+20
∆= 36
x= 4±6/10
x'= 10/10 = 1
x"= -2/10= -1/5
espero ter ajudado