Question

tim so co 2 chu so . so do chia tich cac chu so cua no=3du 11

 

Answer 1

Goi so phai tim la ab {a khac 0; a;b <10}

theo bai ra ta co : 

ab={axb}x3+11

ax10+b=ax3+bx3+11

ax7=bx2+11

vi b la so co 1 chu so =>bx2 +11 la so co 2 chu so =>ax7 la so co 2 chu so 

ta co : 

bx2+11<30 => ax7<30

=>a<5. ma a khac 0 =>a nhan cac gia tri 1;2;3;4

neu a=1 thi 1x7=7=>bx7+11=7{loai}

neu a=2 thi 2x7 = 14 => bx2+11=14 => bx2=3{loai}

neu a=3 thi 3x7=21 => bx2+11=21=> bx2=10 =>b=5{chon}

neu a=4 thi 4x7=28 => bx2+11=28=> bx2=17{loai}

vay ab= 35

k cho minh nha

Answer 2

nay xin loi minh giai nham roi