Answer:
14. x=-2.5, y = -7
15. x=28 y = -20
Step-by-step explanation:
14. Let's solve this system by elimination. Multiply the first equation by -1.
-1*(4x-y)= -1*(- 3)
-4x +y = 3
Then add this to the second equation.
-4x+y = 3
6x-y= - 8
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2x = -5
Divide each side by 2
x = -2.5
We still need to find y
-4x+y =3
-4(-2.5) + y =3
10 +y =3
Subtract 10 from each side.
y = 3-10
y = -7
15.I will again use elimination to solve this system, because using substitution will give me fractions which are harder to work with. I will elimiate the y variable. Multiply the first equation by 11
11(
5x+6y)= 11*20
55x+66y = 220
Multiply the second equation by -6
-6(9x+11y)=32*(-6)
-54x-66y = -192
Add the modified equations together.
55x+66y = 220
-54x-66y = -192
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x = 28
We still need to solve for y
5x+6y = 20
5*28 + 6y =20
140 + 6y = 20
Subtract 140 from each side
6y = -120
Divide by 6
y = -20
6 is the answer 18 divided by 3 equals to 6 so that’s the answer
Answer:
It B ok
Step-by-step explanation:
To solve this problem you must apply the proccedure shown below:
1. You have that:
<span> - The scale model is 11 inches long and 8.5 inches wide.
- The door to her room takes up 1.75 inches.
- The longest wall in Jessica’s actual room is 15 feet long.
2. Therefore, the actual size of the door is:
15 feet=180 inches
1.75 inches(180 inches/11 inches)=28.63 inches
3. If the door in completely open, you must apply the formula for calculate the area of a semicircle:
A=</span>πr²/2
r=28.63 inches
A=π(28.63 inches)²/2
A=1288.11 inches²
The answer is: 1288.11 inches²
