The answer for that equation is A. 16.
5x - 4y = 7
x = 5 - y
5(5 - y) - 4y = 7
25 - 5y - 4y = 7
-5y - 4y = 7 - 25
-9y = - 18
y = -18/-9
y = 2 <== y coordinate is 2
Paul needs to invest $10000 at 6% interest and $30000 at 10% interest to make a total of 9% return on his $40000.
<em><u>Explanation</u></em>
Suppose, the amount of money at 6% interest is
As Paul has total $40000 to invest, so the amount of money at 10% interest will be: 
His intent is to earn 9% interest on his $40000 investment. So, the equation will be......

So, Paul needs to invest <u>$10000 at 6% interest</u> and ($40000- $10000) or <u>$30000 at 10% interest </u>to make a total of 9% return on his $40000.
Let x = John's age now
half of what johns age was 4 years ago: (1/2)(x-4)
is equal to one third of what it will be in 5 years time: (1/3)(x+5)
(1/2)(x-4) = (1/3)(x+5)
3(x-4) = 2(x+5)
3x - 12 = 2x + 10
Answer:

Step-by-step explanation:
1) Rewrite
in the form
, where a = y and b = 1.

2) Use Square of Difference:
.

3) Factor
.
1 - Ask: Which two numbers add up to 6 and multiply to -7?
-1 and 7
2 - Rewrite the expression using the above.

Outcome/Result: 
4) Rewrite the expression with a common denominator.

5) Expand.

6) Collect like terms.

7) Simplify
to 
