Question

aflati x
pana joi
coroana​

Answer 1

3×2^x+2-5×2^x+1-2^x=2

(3×2^2-5×2-1)×2^x=2^1

(12-10-1)×2^x=2^1

1×2^x=2^1

2^x=2^1

x=1

5^x+2-2×5^x+1-12×5^x=375

(5^2-2×5-12)×5^x=375

(25-10-12)×5^x=375

3×5^x=375

5^x=125

5^x=5^3

x=3

2^x×3^x+1=108

2^x×3^x×3=108

(2×3)^x×3=108

6^x×3=108

6^x=36

6^x=6^2

x=2

3^x+1×5^x=675

3^x×3×5^x=675

(3×5)^x×3=675

15^x×3=675

15^x=225

15^x=15^2

x=2

3^x+2×7^x-3^x×7^x+1=2940

$(3 {}^{2} - 7) \times 3 {}^{x} \times 7 {}^{x} = 2940$

$2 \times 3 {}^{x} \times 7 {}^{x} = 2940$

$2 \times 21 {}^{x} = 2940$

$21 {}^{x} = 1470$

$x = log_{21}(1470)$

$x = log_{21}(21 \times 70)$

$x = log_{21}(21) + log_{21}(70)$

$x = 1 + log_{21}(70)$