Answer:
C
Step-by-step explanation: i did it
You can certainly start out that way, but when you solve that equation for x, it's a little more complex than if you started with the other equation. I usually start with the most simple equation first. Let's take the first equation and solve for y... that will leave us without any fractions to deal with.
2x + y = -14
y = -14 - 2x
Now we have a y value and we can substitute it back into the other equation. So we will replace y in the second equation with (-14 - 2x).
That will leave us with just the x as a variable and we can solve for x.
7x - 4y = -19
7x - 4(-14 - 2x) = -19 multiply the -4 through the parentheses
7x + 56 + 8x = -19 combine like terms
15x + 56 = -19 subtract 56 from each side
15x = -75 divide each side by 15
x = -5
Now we have a value for x that we can substitute back into either of the original equations and then solve for y. I usually go with the easier equation, but it doesn't matter. Let's use the first one...
2x + y = -14
2(-5) + y = -14 multiply the 2 through the parentheses
-10 + y = -14 add 10 to each side
y = -4
So your ordered pair is
(-5, -4)
That is where the 2 lines are equal to one another, so that's the point where they they intersect.
Note*** You can start these problems with either equation and solving for either x or y... it doesn't matter. After you substitute the values into the other equation it will work out the same.
Pool and deck = 60 ft by 50 ft
First question: Area of the deck including the deck
A = 60*50 = 3000 ft^2
Average cost = $4,560
Discount offered = 20%
Second question: Cost after discount
This is a question of proportionality. That is;
$4,560 ------------ 100%
Actual cost ------ (100-20)% -----80%
Then,
Actual cost after discount = (4,560*80)/100 = $3,648
Area of the pool is 750 ft^2 and one side is 30 ft.
Third question: Length of the other side
Area = L*W, if Length, L = 30 ft, Width, W = ??
750 = 30*W
W = 750/30 = 25 ft.
Then, the other side is 25 ft long.
Cost per 10 ft length of fence costs $25.50
Fourth question: Total cost of fencing
Circumference = 2(L+W) = 2(60+50) = 220 ft
Number of 10 ft sections = Circumference/10 = 220/10 = 22 sections
Total cost = number of sections*Cost per section = 22*25.50 = $561
One full turn is 360 so the equation would be 360/ 30= 12
Answer:
- 1/4
- 3/5
Step-by-step explanation:
You find the part by expressing the ratio as a fraction, then simplifying.
1. 5/20 = (1·5)/(4·5) = (1/4)·(5/5) = 1/4
5 is 1/4 of 20.
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2. 12/20 = (3·4)/(5·4) = (3/5)·(4/4) = 3/5
12 is 3/5 of 20.