98+8x[1004-4x(8:2x2-4:4x2)]

98+8x[1004-4x(4x2-4:4x2)]

98+8x[1004-4x(8-4:4x2)

98+8x[1004-4x(8-1x2)]

98+8x(1004-4x6)

98+8x(1004-24)

98+8x980

98+7840=7938

[(28x5:2x10)x5]+[31x(600:5+112:4)]-83

[(140:2x10)x5]+[31x(120+28)]-83

[(70x10)x5]+(31x148) - 83

(700x5)+4588-83

3500+4588-83

8088-83=8005

400+480:4+[68:2+4x(20+12+18)]

400+120+[68:2+4x(20+12+18)]

400+120+[(34+4x(20+12+18)]

400+120+(34+4x50)

400+120+(34+200)

400+120+234

520+234=754

68:2+[564:2+4x(31x2+15x3-117:3)]

34+[282+4x(62+45-39)]

34+[2822+4x(107-39)]

34+(282+4x68)

34+(282+272)

34+554=588

94326-123x8:[848:4-(ax100+5x2)]+838149:3=373217

94326-948:[212-(ax100+10)]+279383=373217

94326-948:(212-100a-10)+279383=373217

94326-948:(212-10-100a)+279383=373217

94326-948:(202-100a)+297383=373217

94326-948:2(101-50a)+279383=373217

94326-279383-948:2(101-50a)=373217

373709-948:2(101-50a)=373217

373709-474(101-50a)=373217

-474(101-50a)=373217-373709

-474(101-50a)= - 492

(101-50a)=-474-492

(101-50a)= - 966

-50a= - 966+101

-50a= - 865

a=865:50

a=17,3