No 15 mohon bantuannya kakak Tolong disertai jalan

ma = 2 kg
mb = 3,6 kg
mc = 4,8 kg

Fa,c = Gma.mc/(ra,c)^2
Fa,c = G2(4,8)/5^2
Fa,c = G(9,6)/25 = G(0,384)

Fa,b = Gma.mb/(ra,b)^2
Fa,b = G2(3,6)/(3)^2
Fa,b = G(7,2)/9 = G(0,8)

Fb,c = Gmb.mc/(rb/c)^2
Fb,c = G(3,6)(4,8)/4^2
Fb,c = G(17,28)/16 = G(1,08)

sudut himpit dititik A
tan = de/sa = Fb,c /Fa,b = G(1,08)/G(0,8)
tan = 1,35
teta = 53°

R^2 = Fa,b^2 + Fa,c^2 + 2Fa,b(Fa,c)cos53°
R^2 = (G0,8)^2 +(G0,384)^2 +2(G0,8)(G0,384)(0,6)
R^2 = G^2(0,64 + 0,15 + 2(0,8)(0,384)(0,6)
R^2 = G^2(0,64 + 0,15 + 0,37 )
R^2 = 1,16G^2
R = G√1,16 = G(1,07) = G1,1

semoga bermamfaat ;;)