Answer:
58.3
Step-by-step explanation:
58.3 has the highest unit (the number left of the dot)
- 2 /15 - ( - 9/10 )
-2/15 + 9/10 multiply fraction #1 by 2 an fraction #2 by 3 to get
-4 /30 +27/ 30 = 23/30
The answer: " x = 68, y = 72 " .
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Explanation:
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46 + (x - 3) + (y - 3) = 180 .
46 + 1(x - 3) + 1(y-3) = 180 .
46 + 1x - 3 + 1y - 3 = 180 .
46 - 3 - 3 + 1x + 1y = 180 .
40 + x + y = 180 ;
Subtract "40" from EACH SIDE of the equation:
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40 + x + y - 40 = 180 - 40 ;
to get:
x + y = 140 ;
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Now:
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65 = (x - 3) ;
↔ x - 3 = 65 ;
Add "3" to EACH SIDE of the equation;
x - 3 + 3 = 65 + 3 ;
to get:
x = 68 .
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Now:
Since: "x + y = 140" ;
Let us plug in our known value, "68" ; for "x" ;
to solve for "y" ;
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x + y = 140 ;
68 + y = 140 ;
↔ y + 68 = 140 ;
Subtract "68" from EACH SIDE of the equation; to isolate "y" on one side of the equation; and to solve for "y" ;
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y + 68 - 68 = 140 = 68 ;
y = 72 .
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So, solve for "x" and "y".
x = 68, y = 72 .
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Answer:
number 2
Step-by-step explanation:
3*7*6=126
4*3*10=120
126-120=6
<h2>9.</h2><h3>Given</h3>
<h3>Find</h3>
- linear approximation to the volume when the radius increases 0.4 cm
<h3>Solution</h3>
The equation for volume of a sphere is
... V = (4/3)π·r³
Differentiating gives
... dV = 4π·r²·dr
Filling in the given numbers gives
... change in volume ≈ 4π·(15 cm)²·(0.4 cm)
... = 360π cm³ ≈ 1130.97 cm³ . . . . . . volume of layer 4mm thick
<h2>11.</h2><h3>Given</h3>
- an x by x by 2x cuboid with surface area 129.6 cm²
- rate of change of x is 0.01 cm/s
<h3>Find</h3>
<h3>Solution</h3>
The area is that of two cubes of dimension x joined together. The area of each such cube is 6x², but the two joined faces don't count in the external surface area. Thus the area of the cuboid is 10x².
The volume of the cuboid is that of two cubes joined, so is 2x³. Then the rate of change of volume is
... dV/dt = (d/dt)(2x³) = 6x²·dx/dt
We know x² = A/10, where A is the area of the cuboid, so the rate of change of volume is ...
... dV/dt = (6/10)A·dx/dt = 0.6·(129.6 cm²)(0.01 cm/s)
... dV/dt = 0.7776 cm³/s
