Question

3.Rezolvati in Z ecuatiile
a)9(x-2)=-63
b)5(x+3)=2(5x-5)
c)2(4x+1)=2(5x-7)
d)2(-x+5)=-8(3x+2)+56
e)1-4·[-5 ·(x-2)]=21
f)5(x-2)-7(x+3)+35=0
g)(x+3)(x-7)=0
h)(-2x+6)(x+3)=0


Vă rog frumos să mă ajutați cu aceste ecuații!

Answer 1

am mai facut ex asta .. baftă

Answer 2

a) 9x-18= -63

9x= -63+18

9x= -45

x= -5

b) 5x+15=10x-10

5x-10x= -10-15

-5x= -25

x=5

c) 8x+2=10x-14

8x-10x= -14-2

-2x= -16

x= 8

d) -2x+10= -24x-16+56

-2x+24x= 40-10

22x=30

x=15/11

e) 4*[-5(x-2)]= -20

-5(x-2)= -5

x-2= 1

x=3

f) 5x-10-7x-21+35=0

-2x-31+35=0

-2x+4=0

-2x= -4

x=2

g) x^2-7x+3x-21=0

x^2-4x-21=0

delta=16+84=100

x1=(4+10)/2=14/2=7

x2=(4-10)/2= -6/2= -3 => x={-3, 7}

h) -2x^2-6x+6x+18=0

-2x^2+18=0

2(-x^2+9)=0

-x^2+9=0

-x^2= -9

x^2=9

x= -3 sau 3