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Thepotemich [5.8K]
3 years ago
11

Three-sevenths of a number is 21. Find the number

Mathematics
1 answer:
Neporo4naja [7]3 years ago
6 0
Let x = the unknown number.
Because three-sevenths of the number is 21, therefore
(3/7)x = 21

That is
(3x)/7 = 21

Multiply each side by 7.
3x = 21*7 = 147

Divide each side by 3.
x = 147/3 = 49

Answer:  49
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If g(x)= square root of 3-5x, find the domain of g'(x).
BaLLatris [955]

Answer:

domain: x>3/5

Step-by-step explanation:

First we need to derive our function g(x) to get a new function g'(x)

To do this we will have to apply chain rule because we have an inner and outer functions.

Our G(x) = square root(3-5x)

Chain rule formula states that: d/dx(g(f(x)) = g'(f(x))f'(x)

where d/dx(g(f(x)) = g'(x)

g(x) is the outer function which is x^1/2

f(x) is our inner function which is 3-5x

therefore f'(x)= 1/2x^(-1/2) and f'(x) = -5

g'(f(x)) = -1/2(3-5x)^(-1/2)

Applying chain rule then g'(x) = 1/2 (3-5x)^(-/1/2)*(-5)

But the domain is the values of x where the function g'(x) is not defined

In this case it will be 3-5x > 0, because 3-5x is a denominator and anything divide by zero is infinity/undefined

which gives us x >3/5

5 0
3 years ago
Read 2 more answers
Somebody please help me I’ll give you brainiest if you’re right
Pavlova-9 [17]

Answer: I belive the answer would be 18 the only number we have is 52 and 36 the other answers just don't make sense, I am only taking 9th grade but hey I try!

Step-by-step explanation:

6 0
3 years ago
What is true about the net of a pyramid? It will always contain exactly 1 triangle. It will always contain exactly 2 triangles.
Harrizon [31]

Answer:

im pretty sure its "D" It can contain any number of triangles greater than or equal to 4.

Step-by-step explanation:

7 0
3 years ago
Maritza esta vendiendo una bicicleta seminueva que ya no utiliza. Como le costo doscientos soles, incluido IGV, ahora la venderá
Sophie [7]

Answer:

Ok, primero, como lo deducimos gráficamente?

Sigamos estos pasos.

Dibujemos en una recta, la distancia entre el punto 0 soles y el precio de la bicicleta = 200 soles.

200 soles representa el 100%.

Ella lo quiere vender al 80% (o le quiere restar el 20%).

Entonces, con una regla, medir la distancia entre 0 soles y 200 soles.

Dividir esa cantidad por 10. (cada una de estas cantidades va a representar un 10%)

Multiplicar eso por 8.

Esa cantidad es el equivalente al 80% del precio de la bicicleta.

Abajo hay un dibujo donde se ve el método.

Una forma mas matemática de resolverlo es:

200 soles = 100%.

x soles = 80%

x es el precio al que ella va a vender la bicicleta:

Veamos el cociente de esas dos ecuaciones:

200/x = 100%/80%

x = 200*(80%/100%) = 160

Ella vendería la bicicleta en 160 soles.

8 0
3 years ago
What is the value of the expression below when z = 4?<br> 10z - 3
sergey [27]

Answer:

Your correct answer is 37

Step-by-step explanation:

Evaluate for z = 4

(10)(4)−3

(10)(4)−3

= 37

7 0
3 years ago
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