Answer:
C. 309 cm2
Step-by-step explanation:
A=2(1+sqr2)a^2
A=2(1+sqr2)8^2
≈309.01934
C + a = 138.....c = 138 - a
5.10c + 8.70a = 995.40
5.10(138 - a) + 8.70a = 995.40
703.80 - 5.10a + 8.70a = 995.40
-5.10a + 8.70a = 995.40 - 703.80
3.60a = 291.60
a = 291.60/3.60
a = 81 <===
Answer:
a
Step-by-step explanation:
Given
u = (x₁, y₁, z₁ ) and v = (x₂, y₂, z₂ ) then the dot product is
u • v = (x₁ x₂ ) + (y₁ y₂ ) + (z₁ z₂ )
Then
v • w
= (5 × 9) + (- 4 × - 2) + (4 × 7)
= 45 + 8 + 28
= 81 → a