tang chieu dai mat phang nghieng len 2 lan

khoi luong rieng la1032kg/m3

1

thay b=1/3.a;thay c=1/4.a;thay d=1/5,a

a.(1/3.a)+(1/4.a)binh+(1/5.a)binh=831 tu do tinh a va suy tu tren tinh b,c,d

1/10 lon hon1/15

a+b=a-b<==>2b=0--->b=0va thoa man voi moi a

a)so 2 cuoi

1

sai ta co U2=6/0,6.(0,3+0,6)=9v

vay ta phai dat vao nguon dien co hdt la 9v

dung von ke.ta mac song song voi day dan