Respostas

2014-02-22T16:13:34-03:00
1) {7²-[(6·2)·(24-10²÷5)-2²]}={49-[12·(24-100÷5)-4]}={49-[(12·4-4)-4]}={49-[48-4]}=
={49-44]}=5


2) 60-[40/( \sqrt{4}+3*6) +7*4]/3
=
=60-[(40/(2+18))+28)]/3
60-[((40/20)+28)]/3
60-[2+28]/3
60-[30]/3
60-10=50

3) 60-[20+3*(3*8-14)-49]=
60-[20+3*(24-14)-49]
=60-[20+3*10-49]
60-[20+30-49]=60-1=59