1)
x + 2y = 21
+ -x + 3y = 29
--------------------------
5y = 50
y = 10
x + 2(10) =21
x = 1
2)
6x + 6y = 30
+ 15x - 6y = 12
-------------------------------
21x = 42
x = 2
6(2) + 6y = 30
6y = 18
y = 3
The answer is the first one.
Knowing that population density is like a rate, people per a given area, you would take the amount of people and divide by the area.
3.11E7/7.69E6 = 4.02 people per km squared.
Also the “E” is another way to write times 10 to a power and I recommend using that notation when plugging it into a calculator.
Answer:
(x, y) = (-4, 4)
Step-by-step explanation:
You find the values of x and y by working the problem using any of the methods of solving simultaneous equations that you have been taught.
Here, you observe that the y-coefficients are the same in each equation. That means you can cancel the y-terms by subtracting one equation from the other.
(7x +6y) -(4x +6y) = (-4) -(8)
3x = -12 . . . . simplify
x = -4 . . . . . . divide by 3
Now, you can substitute this into either equation to find y.
4(-4) +6y = 8
6y = 24 . . . . . . . . add 16
y = 4 . . . . . . . . divide by 6
The solution to this system of equation is ...
So let's see here...
6:00 A.M. temperature is 33°F.
12:00 P.M temperature increased by 10°F making it 43°F.
3:00 P.M. temperature increased by another 12°F making it 55°F.
At 10:00 P.M it would decrease by 15°F making it 40°F.
The temperature would need to fall (or decrease) by 7°F to reach the original temperature of 33°F
Hope this helped!
