Answer:
b = 7/2
x = 11/2
y = 21/2
z = -4
Step-by-step explanation:
2x + 2y + 2z = 24
x + y + z = 12
b + 2x + y + z = 21
2b + 2y = 28
b + y = 14
3x + y + z = 23
we can start anywhere by transforming these equations in a way that always one variable is excised by others.
so, e.g.
b = 14 - y
14 - y + 2x + y + z = 21
2x + z = 7
z = 7 - 2x
3x + y + 7 - 2x = 23
x + y = 16
16 + z = 12
z = -4
-4 = 7 - 2x
-11 = -2x
11 = 2x
x = 11/2
11/2 + y = 16
y = 16 - 11/2 = 32/2 - 11/2 = 21/2
b = 14 - 21/2 = 28/2 - 21/2 = 7/2
| u | = √(2² + (-1²)) = √5
| v | = √ ( 1² + (-8)² = √65
cos (u,v) = ( u * v ) / (| u | * | v |) =
(2 * 1 + ( -1 ) * ( - 8 )) / √5 √ 65 = (2 + 8) / √5 √65 = 10 / (√5 √ 65 )
The length of a larger diagonal:
d 1² = | u |² + 2 |u| |v| + | v |² = 5 + (2 √5 √65 * 10 / √5 √65 )+65
d 1² = 70 + 20 = 90
d 1 = √ 90 = 3√10
d 2² = 70 - 20 = 50
d 2 = √50 = 5√2
Answer:
The lengths of the diagonals are: 3√10 and 5√2 .
It should be 80 if I’m correct
Answer:
27 hours
Step-by-step explanation:
Just do the reverse. 65-11 = 54. 54 / 2 = 27.
