解比例和方程.9.4×4-2.2x=842+15x=342x15=54535×(3.5-x)=7557:x=3:411.-数学
题文
解比例和方程. 9.4×4-2.2x=8 42+15x=342
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答案
(1)9.4×4-2.2x=8 37.6-2.2x=8, 8+2.2x=37.6-2.2x+2.2x, 8+2.2x-8=37.6-8, 2.2x÷2.2=29.6÷2.2, x=13
(2)42+15x=342, 42+15x-42=342-42, 15x÷15=300÷15, x=20; (3)
45x=15×5, 45x÷45=15×5÷45, x=1
(4)
3.5-x+x=
x=1
(5)
3x=
3x÷3=
x=
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