Answer:
394.9 cm
Step-by-step explanation:
The formula for a cone's surface area is A = π r ( r + √r^2 + h^2 ).
r = radius
h = height
The Pythagorean theorem, a^2 + b^2 = c^2, will be needed to find the height.
Plug in the values.
a(unknown)^2 + 6^2 = 15^2
A + 36 = 255
255 - 36 = 189
√189 ≈ 13.7
Surface area formula, plug in the values.
A = 3.14 × 6 ( 6 + √6^2 + 13.7^2 )
*PEMDAS*
A = 3.14 × 6 ( 6 + √36 + 187.69 )
A = 3.14 × 6 ( 6 + √223.69 )
A = 3.14 × 6 ( 6 + 14.95 )
A = 3.14 × 6 ( 20.96 )
A = 3.14 × 125.76
A = 394.8864
*round to nearest tenth*
A = 394.9 cm
Hope this helps! :)
26 but use photomath it's a great app that automatically solves math problems of any kind
Answer: x" = 5.69
Step-by-step explanation:
The graphic solution is attached.
Verifying the solution:
Existence condition: x > 0
2x - 4 = √x + 5
√x =2x - 4 - 5
√x =2x - 9 (²)
x = (2x - 9)²
x = 4x² - 36x + 81
4x² - 36x - x + 81 = 0
4x² - 37x + 81 = 0
Δ = -37² - 4.4.81 = 1369 - 1296 = 73
x = 37 ±√73/8
x' = 3.55
x" = 5.69
checking:
2*3.55 - 4 = 3.1
√3.55 + 5 = 6.88 Its not the same ∴ 3.55 is not a solution
2*5.69 - 4 = 7.39
√5.69 + 5 = 7.39 ∴ it's the only solution
P + S = 180
105 + x+65=180
x=10
