All categories

4 years ago

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

2 answers:

7 0

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

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

You might be interested in

HELLOOOO HELP PLEASE

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.

Logarithm of a power:

$log_ba^c=c*log_ba$

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

The Logarithm of a Product:

$log_b{ac}=log_ba+log_bc$

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:

$b^x*b^y=a*c$

Using the exponential identity: $x^{a}*x^b=x^{a+b}$ , we can rewrite the equation as:

$b^{x+y}=ac$

taking the logarithm of both sides, we get:

$log_bac=x+y$

Since x and y are just the logarithms we started with, we can substitute them back in to get: $log_bac=log_ba+log_bc$

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

Furkat [3]

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

3. To solve this you subtract the 50$ from 110$ you get sixty dollars you do that to take out what he earned for his allowance. Then your equation is 60=15x so you divide each side by 15 and when you do that x=4

8 0

3 years ago

3. The circumference of a circle is 607 cm. What is the diameter of the circle?

steposvetlana [31]

Answer:

the circumference is 30 cm,

Step-by-step explanation:

Hope it helps

8 0

2 years ago

WHATS THE ANSWER ILL GIVE BRAINLIEST.

Gemiola [76]

A I’m pretty sure!!!

8 0

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,

a^2 + b^2 = c^2

x^2 + (x + 10)^2 = 50^2

x^2 + x^2 + 20x + 100 = 2500

2x^2 + 20x + 100 = 2500

2x^2 + 20x + 100 - 2500 = 0

2x^2 + 20x - 2400 = 0

2(x^2 + 10x - 1200) = 0

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

3 years ago

Read 2 more answers