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2 years ago

The equation y=19x relates proportional quantities x and y. what is the value of x when y is 4?

Mathematics

2 answers:

Romashka [77]2 years ago

4 0

Answer: The required value of x is $\dfrac{4}{19}.$

Step-by-step explanation: Given that the following equation relates proportional quantities x and y :

$y=19x~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)$

We are to find the value of x when y is 4.

To find the value of x, we must substitute y = 4 in equation (i) and find the corresponding value of x.

From equation (i), we get

$y=19x\\\\\Rightarrow 4=19x\\\\\Rightarrow x=\dfrac{4}{19}.$

Thus, the required value of x is $\dfrac{4}{19}.$

azamat2 years ago

3 0

X = 36

simplify both sides of the equation, isolate the variable,

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The area of a trapezoid is 69.6 in2 and its altitude is 8.7 in. Find the perimeter of the trapezoid if the sum of its legs is eq

Murljashka [212]

To answer this, you will find the sum of the bases by using the area of a trapezoid formula:

A = 1/2 x h x (b1 + b2) - You will represent the area of the 2 bases as x, because it says the sum of the bases so this can be
written as 1 term, x
69.6 = 1/2 x 8.7 x (x); solve for x
69.6 = 4.35x; divide both sides by 4.35
x = 16 in.

If 16 inches is the sum of the 2 bases and the sum of the legs, than you will double this answer to find the perimeter.

16 in x 2 = 32 inches

The perimeter is 32 inches.

7 0

3 years ago

The half life of silicone-32 is 710 years. If 30 grams is present now, how much will be present in 300 years?

Irina18 [472]

Answer:

22.38 g of silicone-32 will be present in 300 years.

Step-by-step explanation:

A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay and its given by

$N(t)=N_0(\frac{1}{2})^{\frac{t}{t_{1/2}}$

where,

$N(t)$ = quantity of the substance remaining

$N_0$ = initial quantity of the substance

$t$ = time elapsed

$t_{1/2}$ = half life of the substance

From the information given we know:

The initial quantity of silicone-32 is 30 g.
The time elapsed is 300 years.
The half life of silicone-32 is 710 years.

So, to find the quantity of silicone-32 remaining we apply the above equation

$N(t)=30\left(\frac{1}{2}\right)^{\frac{300}{710}}=30\left(\frac{1}{2}\right)^{\frac{30}{71}}\approx22.38 \:g$

22.38 g of silicone-32 will be present in 300 years.

7 0

2 years ago

Eight times a number plus five another number is -13. The sum of the two numbers is 1. What are the numbers?

Pani-rosa [81]

Eight *(a number) plus 5*(another number) is -13.

translates to:

8(x) + 5(y) = -13

The sum of (the number) and (the other number) is 1.

translates to:

(x) + (y) = 1

We have a system of two equations involving two unknowns: x and y.

$\rm 8x+5y=-13\\
~~x+~~y=~~~~1$

We can easily solve the system using Substitution or Elimination. Let's use Elimination this time.

We'll multiply the second equation by -8 so that the x's match up.

$\rm ~~~8x+5y=-13\\ -8x-8y=-8$

When we add the equations together, the x's will fall out of the equation, summing to zero. The 5y and -8y will sum to -3y and the right hand side will sum to -21.

$\rm -3y=-21$

Divide by -3,

$\rm y=7$

Plug back into one of your original equations to find the value of x,

$\rm x+y=1\\
x+7=1$

Subtract 7,

$\rm x=-6$

8 0

3 years ago

The original cost of a makeup set was $30. After sales tax, Peter paid a total of $31.71. What is the percent sales tax rate?

S_A_V [24]

Answer:

5.7

Step-by-step explanation:

<u>unrelated</u>, I love how peter is open about buying makeup. i feel as if the gender roles are garbage. #YasQueen #GoPeter #PeterIsCool #MakeupCanBeForBoysToo <3

(also peter could totally be a girl and I am misgendered a person)

6 0

2 years ago

Read 2 more answers

A map is laid out in the standard (x,y) coordinate plane. How long, in units, is an airplane's path on the map as the airplane f

xeze [42]

Answer:

Distance between the points A and B is 15.52 units.

Step-by-step explanation:

It has been given in the question that an airplane flies along a straight line from City A to City B.

Map has been laid out in the (x, y) coordinate plane and the coordinates of these cities are A(20, 14) and B(5, 10).

Distance between two points A'(x, y) and B'(x', y') is represented by the formula,