cho A=3+3^2+3^3+3^4+…………….+3^25 Tìm số dư khi chia A cho 40 17/08/2021 Bởi Madelyn cho A=3+3^2+3^3+3^4+…………….+3^25 Tìm số dư khi chia A cho 40
Đáp án: $A\quad\vdots\quad 40$ Giải thích các bước giải: $A=3+3^2+3^3+3^4+…+3^{25}$ $\rightarrow A=(3+3^2+3^3+3^4+3^5)+(3^6+3^7+3^8+3^9+3^{10})+…+(3^{21}+3^{22}+3^{23}+3^{24}+3^{25})$ $\rightarrow A=3(1+3+3^2+3^3+3^4)+3^{6}(1+3+3^2+3^3+3^4)+…+3^{21}(1+3+3^2+3^3+3^4)$ $\rightarrow A=(1+3+3^2+3^3+3^4)(3+3^{6}+…+3^{21})$ $\rightarrow A=40(3+3^{6}+…+3^{21})$ $\rightarrow A\quad\vdots\quad 40$ Bình luận
Đáp án: $A\quad\vdots\quad 40$
Giải thích các bước giải:
$A=3+3^2+3^3+3^4+…+3^{25}$
$\rightarrow A=(3+3^2+3^3+3^4+3^5)+(3^6+3^7+3^8+3^9+3^{10})+…+(3^{21}+3^{22}+3^{23}+3^{24}+3^{25})$
$\rightarrow A=3(1+3+3^2+3^3+3^4)+3^{6}(1+3+3^2+3^3+3^4)+…+3^{21}(1+3+3^2+3^3+3^4)$
$\rightarrow A=(1+3+3^2+3^3+3^4)(3+3^{6}+…+3^{21})$
$\rightarrow A=40(3+3^{6}+…+3^{21})$
$\rightarrow A\quad\vdots\quad 40$