初二數(shù)學(xué)上冊(cè)實(shí)數(shù)
2020.02.01
發(fā)布者：網(wǎng)上發(fā)布
1.被開方數(shù)含有平方因數(shù)：分解因數(shù)(準(zhǔn)確找到平方因數(shù))
2.被開方數(shù)含有分母：分母變成平方數(shù)
解方程√3 X-1=√2 X
求X
{√5 X-3√ Y=1}
{√3 X-√5 Y=2}
注：X全部不在根號(hào)內(nèi)
√(1/2x)^2+10/9x^2
=√[1/(4x^2)+10/(9x^2)]
=√49/36x^2
若x>0,=7/(6x)
若x<0,=-7/(6x)
√a^4mb^2n+1
=√(a^2mb^n)^2+1
=a^2mb^n+1
√(4a^5+8a^4)(a^2+3a+2)
=√[4a^4(a+2)][(a+2)(a+1)]
=√[4a^4(a+2)^2(a+1)]
=2a^2(a+2)√(a+1)
. 3√(1/6)-4√(50)+30√(2/3)
答案3√(1/6)-4√(50)+30√(2/3)
= 3×√6/6-4×5√2+30×√6/3
=√6/2-20√2+10√6