Pretty sure the answer is 29/20 or 1 9/20. You get this by find the common denominator , 60, and then adding the number all together and simplifying
Multiply the first equation by -2. It turns into 4x+18y=50 and the other one stays -4x-9y=-23. Then you "eliminate" the equations by "adding" them. Set it up like this:
4x+18y=50
+
-4x-9y=-23
4x-4x= 0. 18y-9y= 9y and 50-23= 27
SO: 9y= 27 and y= 3
And then you plug that in to one equation: 4x +18(3)= 50. 4x= 50-(18*3)
4x= -4, so x=-1.
Plug it back in to check!
Hope this helps. Happy solving! :)
Answer:
A. Cylinder + cone
<u>Volume is the sum of volumes:</u>
- V = Vcon + Vcyl = 1/3πr²h₁ + πr²h₂
- V = 1/3π*9²*12 + π*9²*120 = 31554.2 cm³
<u>Surface area of cone:</u>
- A = A=πr(r+√(h₁²+r²)) = π*9(9 + √(9²+12²)) = 678.6 cm²
<u>Surface area of cylinder minus bases:</u>
- A = 2πrh₂ = 2π*9*120 = 6785.8 cm²
<u>Total surface area:</u>
- 678.6 + 6785.8 = 7464.4 cm²
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B. Cube+ pyramid
<u>Volume:</u>
- V = a³ + (1/3)a²h = a³ + (1/3)a²√(l²-(a/2)²)
- V = 8³ + (1/3)8²√(10²-4²) = 707.5 cm³
<u>Surface area of pyramid:</u>
- A = a² + 2al = 8² + 2*8*10 = 224 cm²
<u>Surface area of cube minus bases:</u>
- A = 4a² = 4(8²) = 256 cm²
<u>Total surface area:</u>
Answer:
A Hope this helps
Step-by-step explanation:
