Question

Kaka,... Yg jago/pakar matematika tolong dibantu dengan caranya yah kak. Dikumpulkan segera soalnya....

Answer 1

Dek maaf yg tadi tanggung udah saya ketik.

1)  ³log 45 - ³ log 25 + 9log 75
=  ³log 9.5 -  ³log 5^2 + 3^2 log 25.3
= ³log 9 + ³log 5 - 2 ³log 5 + 3^2 log 5^2 + 3^3 log 3
= ³log 3^2 + ³log 5 - 2 ³log 5 + (2/2) ³log 5 + (1/2) ³log 3
= 2 ³log 3 + ³log 5 - 2 ³log5 + (2/2) ³log 5 + (1/2) ³log 3
= 2 + (1-2+1) ³log 5 + (1/2)
= 2 + 1/2
= 5/2

3)  ²log 64 + ³log 1/27 - 5 log 5 sqr 5
= ² log 2^6 +  ³log 27^-1 - 5log5.5^1/2
= 6 ²log 2 + (-1)  ³log 3^3 - 5log5 + 5log 5^1/2
= 6 + (-3) - 1 + 1/2
= 5/2

6) x1 + x2 = -b:a = -60 : 2 = -30
x1 - x2 = (sqr D)/a 
D = b^2 - 4ac = (60)^2 - 4(2)(-20)
    = 3600 - (-160) = 3760

x1-x2 = (sqr 3760)/2

x1^2 - x2^2 = (x1+x2)(x1-x2)
                  = (-30) ((sqr 3760)/2)
                   = -60 sqr 3760

8) cos x = 1/2 sqrt 2
    x = 45 derajat

10) v.kerucut = 1/3 . phi.r^2 . tinggi
                      = 1/3. (3,14) (1)^2 . 10 cm
                      = 1/3. 3,14. 10 cm
                      = 10,47