a,(6x-72):2-84).28=5628 b,720:(41-(2x+5))=2³.5=8.5=40
⇔(6x-72):2-84=5628:28=201 ⇔41-(2x+5)=720:40=18
⇔(6x-72):2=201+84=285 ⇔2x+5=41-18=23
⇔6x-72=570 ⇔2x=23-5=18
⇔6x=642 ⇔x=18:2
⇔x=642:6 ⇔x=9
⇔x=107
c,2.(x-1)²=128 d,(5x-25).3+144:4=66
⇔(x-1)²=128:2=64=8² ⇔(5x-25).3+36=66
⇔x=8+1=9 ⇔(5x-25).3=66-36=30
, ⇔5x-25=30:3=10
⇔5x=25+10=35⇔x=35:5=7