Question

alguem pode me ajudar por favor com essas questoes

Answer 1

1°
a) 3x=2(x-1)²+3
3x=2.x²-2.x.1+1²+3
3x=2x²-2x+1+3
2x²-2x-3x+1+3=0
2x²-5x+4=0

b)x(x+11)+2(2+21)=0
x²+11x+4+42=0
x²+11x+46=0

C)6(x²-1)-14=5x²+X
6x²-6-14=5x²+X
6x²-5x²-20-x=0
x²-x-20=0

D)(x+2)²+X=0
x²+2.x.2+2²+X=0
x²+4x+4+X=0
x²5x+4=0

2°
a) x²-9x=0

∆=b²-4.a.c
∆= 9²-4.1.0
∆= 81

x'= -B+√∆/2.a
x'= -(-9)+√81/2.1
x'= 9+9/2
x'= 18/2
x'= 9

x''= -b-√∆/2a
x''= -(-9)-√81/2.1
x''= 9-9/2
x''= 0

b) 2x²+4x=0

∆= b²-4. a.c
∆= 4²-4.2.0
∆= 16

x'= -B+√∆/2.a
x'= -4+√16/2.2
x'= -4+4/4
x'= 0

x''= -b-√∆/2.a
x''= -4-√16/2.2
x''= -4-4/4
x''= -8/4
x''= -2