解方程:
(1)(9+Χ):(9-Χ)=5:3????????
(2)x+(3x-16)÷25%=10(x+2)
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解:(1)(9+Χ):(9-Χ)=5:3,
????????????????? 3(9+X)=5(9-X),
???????????????????3×9+3X=5×9-5X,
?????????????????????27+3X=45-5X,
???????????????????? 3X+5X=45-27,
??????????????????????? 8X=18,
?????????????????????8X÷8=18÷8,
???????????????????????? X=2.25;
(2)x+(3x-16)÷25%=10(x+2),
????? x+(3x-16)÷=10x+10×2,
???????x+(3x-16)×4=10x+20,
??????? x+3x×4-16×4=10x+20,
???????????? x+12x-64=10x+20,
??????????? x+12x-10x=20+64,
?????????????????? 3x=84,
??????????????? 3x÷3=84÷3,
??????????????????? x=28.
解析分析:(1)根据比例的意义,两内项之积等于两外项之积,然后去掉括号,再进一步解答即可;(2)根据题意,先去掉括号,然后进一步解答即可.
点评:本题主要考查解方程,根据等式的性质进行解答即可.