We can let
a = 1/(x-1)
b = 1/(y+2)
and rewrite the equations as
2a - b = 10
a + 3b = -9
Using the first to write an expression for b, we get
b = 2a - 10
Substituting this into the second equation gives
a + 3(2a -10) = -9
7a -30 = -9 . . . . . . . . simplify
7a = 21 . . . . . . . . . . .add 30
a = 3
b = 2·3 - 10 = -4
Now, we can find x and y.
3 = 1/(x -1)
x - 1 = 1/3
x = 1 1/3 = 4/3
-4 = 1/(y +2)
y +2 = -1/4
y = -2 1/4 = -9/4
Then the desired sum is
x + y = 4/3 -9/4 = (16 -27)/12
x + y = -11/12
The appropriate choice is ..
c. -11/12
surface area= perimeter x height + 2b
s= pxh+2b
example: 18(8)+2(12)
explain: 18 is the perimeter and 8 is the height then you have to add the base times 2
25365cm÷100=m
=253.65m
25365 is less than 30m
The answer is b. 1/27
3^-3=1/27 and 3^4=81. 1/27×81=3. 3×3=9. 3^-5=1/243. 1/243×9= 1/27. The answer is b. 1/27.
Answer: [D]: " 196π in.³ " .
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Explanation:
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Given: radius, "r", equal 7 in.
Given: height, "h", equals 4 in.
Volume: V = Base area * h ;
The base area of a cone is a circle: A = π * r² = π* (7²) = 49π .
(NOTE: Since all answer choices given are in terms of "π" ; we will leave the units in terms of "π").
V = (Based area) * h = (49π in.) * (4 in.) = (49*4)π in.³
= 196π in.³ ; which is: Answer choice: [D] .
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