Răspuns:
Explicație pas cu pas:
1) 3^(2x-1)=3^(5-x) ⇒2x-1=5-x 3x=6 x=2
2) x+5=4 x=-1
3) x-1=3x-7 3x-x=7-1 2x=6 x=3
4)x-5=4 x=9 x>5
5)1-x=-8 1+8=x x=9
6) x²+3x+2=0
x1,2=-3±√9-8/2=-3±1/2 x1=-2 x2=-1
7) 2x+3=x-1 x=-4
8)2x²+ax-4=0 a=? pt x=-4
2×16-4a-4=0 32-4=4a 28=4a a=7
2x²+7x-4=0
x1,2=-7±√49+32/4 -7±√81/4 x1=-7-9/2=-8 x2=-7+9/2=1
