Giải câu 2 trang 28 sách phát triển năng lực toán 9 tập 1.

a, 13+5+1351.(35)(3+5)(35)+1.(3+5)(35)(3+5)

  = 35+3+59564=32

b, 10+2105+2+815 = 2.5+22.55+2+815

   = 2.5.5+22.55+2+815

   = 25(5+2)5+2+815

   = 25+815 = 25+8.(1+5)15 = 252.(1+5) = -2

c, 43+1+132+633 = 4.(31)31+1.(3+2)34+6.(3+3)39 

  = 2.(31)(3+2)(3+3) = -7

d, 2+32+2+3+232232.(2+3)2.(2+2+3)+2.(23)2.(223)

 = 2.(2+3)2+4+23+2.(23)2423 = 2.(2+3)2+3+23+1+2.(23)2323+1

 = 2.(2+3)2+(3+1)2+2.(23)2(31)2 = 2.(2+3)2+3+1+2.(23)23+1

 = 2.(2+3)3+3+2.(23)33 = 2.(2+3).(33)93+2.(23).(3+3)93

 = 2.(2+3).(33)+2.(23).(3+3)6 = 626 = 2

e, 555+5+5+555 = (55).(55)255+(5+5).(5+5)255

 = (25105+5)+(25+105+5)20 = 6020 = 3

f, 33+1133+1+1 = 3.(3+1+1)3+113.(3+11)3+11

  = 3.(3+1+1)33.(3+11)3 = 3+1+1(3+11) = 2