Answer:
48
Step-by-step explanation:
3(22)+4(32)
=(3)(4)+4(32)
=12+4(32)
=12+(4)(9)
=12+36
=48
Answer:
n = 9
Step-by-step explanation:
20 + 18 + ... + 6 + 4
---------------------------
a = 20 ; d = -2 ; n = ?
--------
4 = 20 + (n-1)(-2)
-16 = (n-1)(-2)
---------
n-1 = 8
n = 9
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S(9) = (9/2)(20+4)
S(9) = 4.5*24
S(9) = 108
12.................................................
30 percent of 52= 15.6
52.00-15.60= 36.40
$36.40
Surface area of the prism is 2xy+2xz+2yz
I think, we can cut hole on the face of the prisma 40x30, and size of the whole will be 5X5X5
hole increases surface area. If side of the cube is "a", then a^2 is the area of the one face of the cube.
when we are doing the hole, we remove 2 faces and add 4 more faces, so
2xy+2xz+2yz-2a^2+4a^2= 2xy+2xz+2yz+2a^2
So, 2*5*40+2*5*30+2*40*30+2*5^2=3150 cm^2
i hope it helps, it is what i can come up with now