Toán Lớp 7: Thực hiện phép tính sau: a)[($3^{14}$ .69+$3^{14}$ .12):$3^{16}$-7]: $2^{4}$ b)$24^{4}$ :$3^{4}$ -$32^{12}$ :$16^{12}$

Question

Toán Lớp 7:  Thực hiện phép tính sau: a)[($3^{14}$ .69+$3^{14}$ .12):$3^{16}$-7]: $2^{4}$  b)$24^{4}$ :$3^{4}$ -$32^{12}$ :$16^{12}$

mocmien87 · Answer

a, [(3^{14} . 69 + 3^{14} . 12) : 3^{16} - 7] : 2^{4}   = {[3^{14} . (69 + 12)] : 3^{16} - 7} : 2^{4}   = {[3^{14} . 81] : 3^{16} - 7} : 16   = {[3^{14} . 3^{4}] : 3^{16} - 7} : 16   = {3^{18} : 3^{16} - 7} : 16   = {3^{2} - 7} : 16   = {9 - 7} : 16   = 2 : 16   = 1/8   _________________   b, 24^{4} : 3^{4} - 32^{12} : 16^{12}   = 2^{12} . 3^{4} : 3^{4} - 2^{60} : 2^{48}   = 2^{12} . (3^{4} : 3^{4}) - (2^{60} : 2^{48})   = 2^{12} . 1 - 2^{12}   = 2^{12} - 2^{12}   = 0

hienchaudiem · Answer

~ Bạn tham khảo ~    a, [(3^14*69+3^14*12)&divide;3^16-7]&divide;2^4   = [3^14*(69+12)&divide;3^16-7]&divide;2^4   = (3^18&divide;3^16-7)&divide;2^4   = (3^2-7)&divide;2^4   = 2&divide;2^4   = 2^(-3)   = 0,125   b, 24^4&divide;3^4-32^12&divide;16^12   = (24&divide;3)^4-(32&divide;16)^12   = 8^4-2^12   = 2^12-2^12   =0