Answer:
Explanation:
3 + 2x - y = 0
Or 2x - y = -3 (1)
-3-7y = 10x
Or -10x - 7y = 3 (2)
2x - y = -3 (1)
-10x - 7y = 3 (2)
———————
Multiply 5 to (1)
5(2x - y = -3)
-10x - 7y = 3
———————
10x - 5y = -15
-10x - 7y = 3
———————
-12y = -12
y = -12/-12
y = 1
Plug y value in (1)
2x - 1 = -3
2x = -3 + 1
2x = -2
x = -2/2 = -1
Therefore, x = -1 and y = 1
For these problems you have to use PEMDAS so for problem 15 you would do the parentheses first, (21-3) you get 18 and then exponents, 3^2, you get 9, no multiplication but there is division so take your answers, 18 and 9 and divide them, you get 2, so the answer to 15 is 2.
The population in 2040 of the town can be solved using the formula
F = P( 1 -I)^n
Where F is the future population
P is the present population
I is the decline rate
N is the number of years
F = 22,000(1-0.028)^39
<span>F = 7268</span>
Ok so the answer is

so we multiply numbers that have the same variable

multiply 2 x 2

then multiply the exponents

multipling like this will look like addition.

so in other words you could do it like this too

now add the exponent with 4

now for the last part

because -3 and 3 added together make 0

I hope this help(it looks complicated but it's very easy and I hope I helped you out)
Answer:................................................................................................
15