Question

Rezolvați in Q ecuațiile:
3x-8=5-7x
3x-1/2=3/2=7
5x-4/3
3x+7/2=3/2
X+1=2(x-1)
3(x+2)-4(x-1)=-7(x+2)

Answer 1

a)3x-8=5-7x
3x+7x=5+8 (separam termenii cu x de cei fara)
10x=13
x=13:10
x=13/10 apartine Q (fractiile sunt in Q)
b) nu apartine lui Q e intrebare capcana
c)5x-4/3
=5x-4/3 apartine lui Q
d)3x+7/2=3/2
3x+7/2=3:2
3x+7/2=3/2
3x=3/2-7/2
3x=3-7/2
3x=-4/2
3x=-2
x=-2:3
x=-2/3
x=- 2/3 apartine Q
x+1=2(x-1)
x+1=2*x-2*1
x+1=2*x-2
x+1=2x-2
x-2x=-2-1
-x=-2-1
-x=-3
x=3 nu apartine de Q
ultima nu stiu