Salut! ♡
Exercițiul 20
a)
[tex]3 {}^{x} + 3 {}^{x - 1} = 4[/tex]
[tex](3 + 1) \times 3 {}^{x - 1} = 4[/tex]
[tex]4 \times 3 {}^{x -1} = 4[/tex]
[tex]3 {}^{x - 1} = 1[/tex]
[tex]3 {}^{x - 1} = 3 {}^{0} [/tex]
[tex]x - 1 = 0[/tex]
[tex]x = 1[/tex]
c)
[tex]5 \times 3 {}^{x} - 2 \times 3 {}^{x} = 81[/tex]
[tex]3 \times 3 {}^{x} = 3 {}^{4} [/tex]
[tex]3 {}^{x - 1} = 3 {}^{4} [/tex]
[tex]x - 1 = 4[/tex]
[tex]x = 4 - 1[/tex]
[tex]x = 3[/tex]
Exercițiul 21
a) (16×12¹⁰-4×12¹⁰) : 12¹¹
12×12¹⁰:12¹¹=1
c) 10³×85-10³×61-3000
85× 10³-61×10³-3000
24×10³-3000
24×1000-3000
24000-3000
21000
Succes!
Coroniță? ♡
