解方程. 5x-3.7=8.5 x-13=104 3x-x=41.6 3.2÷4x=0.01 4 5 x ÷ 1 2 = 7 10 2 3 x+ 1 2 = 7 8 .
(1)5x-3.7=8.5 5x-3.7+3.7=8.5+3.7 5x=12.2 5x÷5=12.2÷5 x=2.44; (2)x-13=104 x-13+13=104+13 x=117; (3)3x-x=41.6 2x=41.6 2x÷2=41.6÷2 x=20.8; (4)3.2÷4x=0.01 3.2÷4x×4x=0.01×4x 3.2=0.04x 0.04x÷0.04=3.2÷0.04 x=80; (5)
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