初一数学、快点、①.(13x-11y+10z)-(15x+10y-15z)②.2(3a+5b)+3(5a-7b)-1/2
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初一数学、快点、
①.(13x-11y+10z)-(15x+10y-15z)
②.2(3a+5b)+3(5a-7b)-1/2(2a-4b)
③.1/2x-2(-x-1/3y^2)+2(-3/4x+1/6y^2)
④.3a^2b-[2ab-(2ab^2-a^c)-(-2ab^2+a^2c)]
要过程、至少2步
①.(13x-11y+10z)-(15x+10y-15z)
②.2(3a+5b)+3(5a-7b)-1/2(2a-4b)
③.1/2x-2(-x-1/3y^2)+2(-3/4x+1/6y^2)
④.3a^2b-[2ab-(2ab^2-a^c)-(-2ab^2+a^2c)]
要过程、至少2步
①.(13x-11y+10z)-(15x+10y-15z)
=13x-11y+10z-15x-10y+15z
=-2x-21y+25z
②.2(3a+5b)+3(5a-7b)-1/2(2a-4b)
=6a+10b+15a-21b-a+2b
=20a-9b
③.1/2x-2(-x-1/3y^2)+2(-3/4x+1/6y^2)
=1/2x+2x+2/3y^2-3/2x+1/3y^2
=x+y^2
④.3a^2b-[2ab-(2ab^2-a^c)-(-2ab^2+a^2c)]
=3a^2b-2ab+(2ab^2-a^c)+(-2ab^2+a^2c)
=3a^2b-2ab+2ab^2-a^c-2ab^2+a^2c
=3a^2b-2a
=13x-11y+10z-15x-10y+15z
=-2x-21y+25z
②.2(3a+5b)+3(5a-7b)-1/2(2a-4b)
=6a+10b+15a-21b-a+2b
=20a-9b
③.1/2x-2(-x-1/3y^2)+2(-3/4x+1/6y^2)
=1/2x+2x+2/3y^2-3/2x+1/3y^2
=x+y^2
④.3a^2b-[2ab-(2ab^2-a^c)-(-2ab^2+a^2c)]
=3a^2b-2ab+(2ab^2-a^c)+(-2ab^2+a^2c)
=3a^2b-2ab+2ab^2-a^c-2ab^2+a^2c
=3a^2b-2a
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