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Svetach [21]
3 years ago
13

I forgot how to do these, could somebody explain. 30 points for both

Mathematics
1 answer:
Aleonysh [2.5K]3 years ago
7 0

Answer:

11) A

12) B

Step-by-step explanation:

11) 10x² + 1 = 0

Subtract 1 from both sides:

10x² = -1

Divide both sides by 10:

x² = -1/10

Take the square root of both sides:

x = ±√(-1) / √(10)

Remember that the square root of -1 is i:

x = ±i / √(10)

To rationalize the denominator, multiply top and bottom by √10.

x = ±i√(10) / 10

Answer is A.

12) 2v² + 8v + 6 = 0

Divide both sides by 2:

v² + 4v + 3 = 0

Use AC method or quadratic formula to factor:

(v + 1) (v + 3) = 0

Set each expression to 0:

v + 1 = 0 or v + 3 = 0

Solve:

v = -1 or v = -3

Answer is B.

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Using f(x)=2x^2 and g(x)=3x+4. whats (g of f)(5)? <br>whats (f of g)(5)?​
3241004551 [841]

Answer:

f(g(x)) = 722, and g(f(x)) = 154

Step-by-step explanation:

f(x) = 2x²

g(x) = 3x + 4

g(f(x)) = 3(2x²) + 4

g(f(5)) = 3(2 × 5²) + 4

g(f(5)) = 3(2 × 25) + 4

g(f(5)) = 3 × 50 + 4

g(f(5)) = 154

f(g(x)) = 2(3x + 4)²

f(g(5)) = 2(3 × 5 + 4)²

f(g(5)) = 2 × 19²

f(g(5)) = 2 × 361

f(g(5)) = 722

7 0
3 years ago
What is the answer?<br><br> Y= -x-4 <br> Y=x
Mashcka [7]
Do you mean like this?

Y = -x - 4
Y = x

x = -x - 4
2x = -4
x = -2

Therefore y = -2
7 0
3 years ago
Which choice is equivalent to the expression below?
enyata [817]

Answer: B

Step-by-step explanation:

3 0
3 years ago
Water is leaking out of an inverted conical tank at a rate of 6800 cubic centimeters per min at the same time that water is bein
ivanzaharov [21]

Answer:

1508527.582 cm³/min

Step-by-step explanation:

The net rate of flow dV/dt = flow rate in - flow rate out

Let flow rate in = k. Since flow rate out = 6800 cm³/min,

dV/dt = k - 6800

Now, the volume of a cone V = πr²h/3 where r = radius of cone and h = height of cone

dV/dt = d(πr²h/3)/dt = (πr²dh/dt)/3 + 2πrhdr/dt (since dr/dt is not given we assume it is zero)

So, dV/dt = (πr²dh/dt)/3

Let h = height of tank = 12 m, r = radius of tank = diameter/2 = 3/2 = 1.5 m, h' = height when water level is rising at a rate of 21 cm/min = 3.5 m and r' = radius when water level is rising at a rate of 21 cm/min

Now, by similar triangles, h/r = h'/r'

r' = h'r/h = 3.5 m × 1.5 m/12 m = 5.25 m²/12 m = 2.625 m = 262.5 cm

Since the rate at which the water level is rising is dh/dt = 21 cm/min, and the radius at that point is r' = 262.5 cm.

The net rate of increase of water is dV/dt = (πr'²dh/dt)/3

dV/dt = (π(262.5 cm)² × 21 cm/min)/3

dV/dt = (π(68906.25 cm²) × 21 cm/min)/3

dV/dt = 1447031.25π/3 cm³

dV/dt = 4545982.745/3 cm³

dV/dt = 1515327.582 cm³/min

Since dV/dt = k - 6800 cm³/min

k = dV/dt - 6800 cm³/min

k = 1515327.582 cm³/min - 6800 cm³/min

k = 1508527.582 cm³/min

So, the rate at which water is pumped in is 1508527.582 cm³/min

5 0
3 years ago
Sally and Eddy had a total of $580 after spending $80 and eddy had 240 left how much money does Sally have?​
levacccp [35]

Answer:

260

Step-by-step explanation:

8 0
3 years ago
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