Question

初一数学计算化简求值题

①.-1/27（a-b）^9 ÷ 1/9（b-a）^3

②.已知：丨a+1/2丨 + (b-3)^2=0,求[(2a+b)^2 + (2a+b)*(b-2a)-6b]÷2b

③.已知x+5y=6,求x^2 +5xy+30y
为什么就是没有人能列式呢

Answer 1

①.-1/27（a-b）^9 ÷ 1/9（b-a）^3
= 1/27（b-a）^9 ÷ 1/9（b-a）^3
=1/3 （b-a）^6
②丨a+1/2丨=0 (b-3)^2=0
a=-1/2 b=3
[(2a+b)^2 + (2a+b)*(b-2a)-6b]÷2b
=[(2a+b)(2a+b+ b-2a)-6b]÷2b
=[(2a+b)-3b]
=2(a-b)
=-7
③.x^2 +5xy+30y
=x(x+5y)+30y
=6x+30y
=6(x+5y)
=36

Answer 2

1. 3
2. 由已知得a=-1/2,b=3,故原式=-2
3. x（x+5y）+30y=6x+30y=6(x+5y)=36

Answer 3

3，x^2+5xy+30y=x(x+5y)+30y=6x+30y=6(x+5y)=36