One year, the population of a city was 400,000. Several years later it was 340,000. Find the percent decrease.

Follow the directions to solve the system of equations by elimination. 8x + 7y=39 4x – 14y = -68

harina [27]

Step-by-step explanation:

Hey there!

Here;

The equations are;

$8x + 7y = 39.......(i)$

$4x - 14y = - 68..........(ii)$

Multiplying equation (i) by 2.

16x + 14y = 78

4x - 14y = -68

20x = 10

$x = \frac{10}{20}$

x = 1/2.

Putting value of 'x' in equation (i).

$8 \times \frac{1}{2} + 7y = 39$

$4 + 7y = 39$

$7y = 3 9 - 4$

$y = \frac{35}{7}$

Therefore the value of y is 5.

Check:

Put value of x and y in equation (i).

8x + 7y = 39

$8 \times \frac{1}{2} + 7 \times 5 = 39$

$4 + 35 = 39$

$39 = 39$

(True).

Therefore, the solution is ; (1/2,5).

Hope it helps...

8 0

3 years ago

Which property of multiplication is shown? 6 · 1 = 1 · 6

saw5 [17]

Answer: Commutative property of multiplication

Step-by-step explanation: The problem 6 · 1 = 1 · 6 demonstrates the commutative property of multiplication.

In other words, the commutative property of multiplication says that changing the order of the factors does not change the product.

So for example here, 6 · 1 is equal to 6 and 1 · 6 also equals 6.

Since 6 = 6, we can easily see that 6 · 1 must be equal to 1 · 6.

In more general terms, the commutative property of multiplication can be written as a · b = b · a where a and b are variables that can represent any numbers.

5 0

2 years ago

Read 2 more answers

Of the students on the track team, 1twelve do the high jump. Of those students 1fourth alsobdo of the long jump. What fraction o

raketka [301]

1/3 fraction of the students have done both

5 0

2 years ago

Read 2 more answers

A circle has an area of 40 square inches. Find the radius to 2 decimal places.

Oksanka [162]

The area of a circle is given by

$A=\pi r^2$

We can solve this equation for r: divide both sides by pi:

$r^2=\dfrac{A}{\pi}$

Consider the (positive) square root of both sides:

$r = \sqrt{\dfrac{A}{\pi}}$

So, in your case, we have

$r = \sqrt{\dfrac{40}{\pi}}\approx 3.57$

7 0

3 years ago

PLEASE HELP

Alex73 [517]

Because we don't have any set numbers for x or y, I believe that the solution set for both equations are infinite.

8 0

3 years ago