Question

calcule as raizes de cada equação:a)x²+5x=0,b)-x²+4x=0,c)3x²-27x=0,d)11x²-x=0
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Answer 1

a)X²+5X=0

X×(X+5)=0

X=0

X+5=0 -> X=-5

(0;-5)

b) -X²+4X=0

-X×(4+X)=0

X=0

4+X=0 -> X=4

(0;4)

c)3X²-27=0

27²-4×3×0= 729

-

$\frac{ - 27 + \sqrt{729} }{2 \times 3} = 0$

$\frac{ -27 - \sqrt{729} }{2 \times 3} =9$

(0;9)

d) 11x²-x=0

X×(11x- 1)=0

X=0

11X-1=0

X=1/11

(0;1/11)