2)41×(28-x)=1066
41×28-41x=1066
1148-41x=1066
-41x=1066-1148
-41x=-82
x=-41÷(-82)
x=2
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4)14×(z+19)=378
14z+14×19=378
14z×266=378
14z=387-266
14z=112
z=112÷14
z=8
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6)81×(b+47)=4374
81b+81×47=4374
81b+3807÷4374
81b=4374-3807
81b= 567
b=567:81
b=7
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