Question

3la puterea x+2-5×3la puterea x=36

Answer 1

$3^{x+2}-5\cdot 3^x=36\\3^x\cdot 3^2-5\cdo 3^x=36\\3^x(3^2-5)=36\\3^x(9-5)=36\\3^x\cdot 4=36\\3^x=9\\3^x=3^2\\\boxed{x=2}$

Answer 2

${3}^{x + 2} - 5 \times {3}^{x} = 36 \\ \\ ( {3}^{2} - 5) \times {3}^{x} = 36 \\ \\ (9 - 5) \times {3}^{x} = 36 \\ \\ 4 \times {3}^{x} = 36 \\ \\ 4 \times {3}^{x} : 4 = 36 : 4 \\ \\ {3}^{x} = 36 : 4 \\ \\ 3x = 9 \\ \\ {3}^{x} = {3}^{2} \\ \\ x = 2$