3 ∗ 2 x + 3 − 5 ∗ 2 x + 1 − 2 x + 2 = 40 {\displaystyle 3*2^{x+3}-5*2^{x+1}-2^{x+2}=40}
3 ∗ 2 x + 3 − 5 ∗ 2 x + 1 − 2 x + 2 = 40 2 x + 2 ( 3 ∗ 2 − 1 ) − 5 ∗ 2 x + 1 = 2 x + 2 = 2 3 ∗ 5 2 x + 2 ∗ 5 − 5 ∗ 2 x + 1 = 2 x + 2 = 2 3 ∗ 5 2 x + 1 ∗ 5 ( 2 − 1 ) = 2 x + 2 = 2 3 ∗ 5 x + 1 = 3 x = 2 {\displaystyle {\begin{aligned}3*2^{x+3}-5*2^{x+1}-2^{x+2}=40\\2^{x+2}(3*2-1)-5*2^{x+1}=2^{x+2}=2^{3}*5\\2^{x+2}*5-5*2^{x+1}=2^{x+2}=2^{3}*5\\2^{x+1}*5(2-1)=2^{x+2}=2^{3}*5\\x+1=3\\x=2\end{aligned}}}
