Answer:
314 m²
Step-by-step explanation:
the formula for the surface area of a sphere (As) is
As = 4×pi×r²
the radius r (half of the diameter) is clearly indicated as 5m.
so, As = 4×3.14×5² = 4×3.14×25
I don't even need a calculator for this, as 4×25 = 100
so, As = 100×3.14 = 314
(you know, when multiplying by 10, the decimal point moves right one position. multiply by 100 it moves 2 positions, and so on).
3x^2+11x-4=10x-1
3x^2+11x-10x-4+1=0
3x^2+x-3=0
Δ=1^1-4*3*(-3)=1+36=37
x1=(-1+V37)/6
x2=( -1-V37)/6
Answer:
1. B) 5.7
2. A) 12
3. A) 11.4
4. A) 5.7
5. A) 16.2
6. A) 11.2
7. No, they do not form a right triangle
8. Yes, they do form a right triangle
Step-by-step explanation:
Extra tip: The hypotenuse has to be less than both sides added together, but cannot be more than either of the sides alone.
1.
16² + b² = 17²
256 + b² = 289
256 - 256 + b² = 289 - 256
b² = 33
√b² = √33
b = 5.74 or 5.7
2.
16² + b² = 20²
256 + b² = 400
256 - 256 + b² = 400 - 256
b² = 144
√b² = √144
b = 12
3.
7² + 9² = c²
49 + 81 = c²
130 = c²
√130 = √c²
11.40 or 11.4 = c
4.
7² + b² = 9²
49 + b² = 81
49 - 49 + b² = 81 - 49
b² = 32
√b² = √32
b = 5.65 or 5.7
5.
a² + 5² = 17²
a² + 25 = 289
a² + 25 - 25 = 289 - 25
a² = 264
√a² = √264
a = 16.24 or 16.2
6.
10² + b² = 15²
100 + b² = 225
100 - 100 + b² = 225 - 100
b² = 125
√b² = √125
b = 11.18 or 11.2
7.
15² + 8² = 16²
225 + 64 = 256
289 ≠ 256
8.
5² + 12² = 13²
25 + 144 = 169
169 = 169
Answer:
x = -2
Step-by-step explanation:
