a.58+42+32+58+72+42 b.133:7+154:7+413:7:4
=(58+42)+(58+42)+72+32 =133:7+154:7+413:4:7
=100+100+72+32 = 133:7+154:7+103,25 :7
=200+104 = (133+154+103,25):7
=304 = 390,25:7
= 55.75
\(a.58+42+32+58+72+42\)
\(=\left(58+42\right)+\left(58+42\right)+72+42\)
\(=100+100+104\)
\(=304\)