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Umnica [9.8K]
4 years ago
7

What is the value of x in the equation x – y = 30, when y = 15?

Mathematics
2 answers:
MrMuchimi4 years ago
7 0
<span>x+y=30.....(1) and x-y=2......(2) so(1)+(2)......x+y+x-y=30+2 so 2x=32...x=16 now apply x=16 in (1) so we get......16+y=30 so .......y=14</span>
forsale [732]4 years ago
3 0
Plug in y.

x-15= 30

Add 15 to the other side.

x= 45

I hope this helps!
~kaikers
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MA_775_DIABLO [31]

Answer:

2*log(x)+log(y)

Step-by-step explanation:

So, there are two logarithmic identities you're going to need to know.

<em>Logarithm of a power</em>:

   log_ba^c=c*log_ba

   So to provide a quick proof and intuition as to why this works, let's consider the following logarithm: log_ba=x\implies b^x=a

   Now if we raise both sides to the power of c, we get the following equation: (b^x)^c=a^c

   Using the exponential identity: (x^a)^c=x^{a*c}

    We get the equation: b^{xc}=a^c

    If we convert this back into logarithmic form we get: log_ba^c=x*c

    Since x was the basic logarithm we started with, we substitute it back in, to get the equation: log_ba^c=c*log_ba

Now the second logarithmic property you need to know is

<em>The Logarithm of a Product</em>:

    log_b{ac}=log_ba+log_bc

    Now for a quick proof, let's just say: x=log_ba\text{ and }y=log_bc

    Now rewriting them both in exponential form, we get the equations:

    b^x=a\\b^y=c

    We can multiply a * c, and since b^x = a, and b^y = c, we can substitute that in for a * c, to get the following equation:

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   taking the logarithm of both sides, we get:

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Now let's use these identities to rewrite the equation you gave

log(x^2y)

As you can see, this is a log of products, so we can separate it into two logarithms (with the same base)

log(x^2)+log(y)

Now using the logarithm of a power to rewrite the log(x^2) we get:

2*log(x)+log(y)

3 0
2 years ago
Luke earns $50 for doing his chores each month. He washes cars in his neighborhood for $15 each. Last month he earned a total of
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Answer:

He washed 4 cars.

Step-by-step explanation:

1. The variable that was unknown x amount of cars washed.

2.The equation I used was 110-50=15x

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3 years ago
3. The circumference of a circle is 607 cm. What is the diameter of the circle?
steposvetlana [31]

Answer:

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Step-by-step explanation:

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2 years ago
WHATS THE ANSWER ILL GIVE BRAINLIEST.
Gemiola [76]
A I’m pretty sure!!!
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3 years ago
What is the value of x in the diagram?
dalvyx [7]

Answer:

x = 30

Step-by-step explanation:

here 50 is hypotenuse as it is opposite of 90 degree.

x and x + 10 are the two other smaller sides of a right angled triangle respectively.

using pythagoras theorem,

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x^2 + 10x - 1200 = 0

x^2 + (40 - 30) - 1200 = 0

x^2 + 40x - 30x - 1200 = 0

x(x + 40) - 30(x + 40x) = 0

(x + 40)(x - 30) = 0

either x + 40 = 0          OR x - 30 = 0

x = 0 - 40

x = -40

x - 30 = 0

x = 30

x = -40,30

since the length and distance is not measured in negative ur answer will be 30

credit goes to sreedevi102

thank u very much . At first i was wrong and giannathecookie i m really sorry

3 0
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Read 2 more answers
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