if `a=3,b=0,c=2`and `d=1` ,find the vale `3a+3b-6c+4d`

If a+b+c=6\ a n d\ a b+b c+c a=11 , find the value of a^3+b^3+c^3-3a b c

If a= 2b/3, b= 2c/3, and c=2d/3, then find the ratio of b and d:

For a real number a with 0 lt a lt (1)/(2) , if b = 1 - a + a^(2) - a^(3) + …, c = 1 - b + b^(2) - b^(3)+… and d = 1 + c + c^(2) +… , find the value of (d-a)

If A : B = 1 : 2, B : C = 3 : 4 and C : D = 5 : 6, then find the value of D : C : B.

If a, b, c, d satisfy the equation a + 7b + 3c + 5d = 0 , 8a + 4b + 6c + 2d = - 16 , 2a + 6b + 4c + 8d =16 and 5a + 3b + 7c + d = -16 then the value of (a + d) (b + c) =______

If a: b= 2: 3, b: c= 4: 5 and c: d= 6: 7 , find : a: b: c:d .

If A, B, C, D are the points (3,4,5),(4,6,3),(-1,2,4) and (1,0,5) , find the angle between C D and A B

If a,b,c and d satisfy the equation a+7b+3c+5d=0,8a+4b+6c+2d=-162a+6b+4c+8d=16,5a+3b+7c+d=-16 then (a+d)(b+c) equation