1.√(25x⁴/9y²)=5x²/(3︱y︱);
2.√(3/100)=(√3)/10;
3.√[1+(15/49)]=√(64/49)=8/7;
4.√(49*9/169 )=(7×3)/13=21/13;
5.14/√76=14/(2√19)=7/√19=(7/19)√19;
6.√72/√6=√12=2√3
7.若X=2/(√3-1),求X²-X+1的值
x=2/(√3-1)=√3+1;故x²-x+1=(√3+1)²-(√3+1)+1=4+2√3-√3=4+√3.
1.√(25x⁴/9y²)=5x²/(3︱y︱);
2.√(3/100)=(√3)/10;
3.√[1+(15/49)]=√(64/49)=8/7;
4.√(49*9/169 )=(7×3)/13=21/13;
5.14/√76=14/(2√19)=7/√19=(7/19)√19;
6.√72/√6=√12=2√3
7.若X=2/(√3-1),求X²-X+1的值
x=2/(√3-1)=√3+1;故x²-x+1=(√3+1)²-(√3+1)+1=4+2√3-√3=4+√3.