二次根式1.算式后面的2是平方的意思``1.(根号12+5倍根号8)乘根号3 2.(2倍根号3+3倍根号2)(2倍根号3

5个回答

  • (√12+5√8)*√3

    =(2√3+10√2)*√3

    =6+10√6

    (2√3+3√2)(2√3-3√2)

    =(2√3)^2-(3√2)^2

    =12-18

    =-6

    (2√3+2√5)^2

    =(2√3)^2+2(2√3)(2√5)+(2√5)^2

    =12+8√15+20

    =32+8√15

    (√48+√6/4)/√27

    =(4√3+√6/4)/3√3

    =(4√3)/3√3+√6/(4*3√3)

    =4/3+(√2)/12

    [√24-√(1/2)]-[√(1/8)+√6]

    =2√6-√2/2-√2/4-√6

    =√6-3(√2)/4

    2√12*(√3/4)/5√2

    =(2*1/4*1/5)*√(12*3/2)

    =(1/10)*√18

    =3(√2)/10

    (2√3+√6)(2√3-√6)

    =(2√3)^2-(√6)^2

    =12-6

    =6

    (2√48-3√27)/√6

    =(8√3-9√3)/√6

    =-√3/√6

    =-√(1/2)

    =-(√2)/2