[(72:a-3x4)x36-19x5] -(124x6-301x2)=195
[(72:a -12)x36-95]-(744-602)=195
[(72:a-12)x36-95]-142=195
(72:a-12)x36-95=195+142
(72:a-12) x36=337+95
(72:a-12)x36=432
72:a-12=432:36
72:a-12=12
72:a=12+12
72:a=24
a=72:24
a=3
