Question

o por soma e produto:?
a) 12x+28=x²
b) x²+63=16x
c)15x=3x²+12
d) (x+6)²=25x-4

Answer 1

12x+28=x²
-x²+12x+28=0
∆= b²-4.a.c
∆= 12²4.(-1).28
∆=√256
∆= 16
X= -b±√∆\2.a

x'= -12+16/-2
x'= -2

x"= -12-16/-2
x"= 14
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x²+63=16x
x²-16x+63=0

x"= 16-4/2
x"= 6

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15x=3x²+12
-3x²+15x-12=0
-x²+5x-4=0

∆= b²-4.a.c
∆= 5²4.(-1).(-4)
∆=√9
∆= 3
X= -b±√∆\2.a

x'= -5+3/-2
x'= 1

x"= -5-3/-2
x"= 4
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