Answer:
A. x=3, y= -6
Step-by-step explanation:
x - 2y = 15
2x + 4y= -18
<em>Solving for x</em>
x-2y=15
<em>Subtract x from both sides</em>
-2y= -x+15
<em>Multiply both sides by -1</em>
2y=x-15
<em>Multiply both sides by 2</em>
4y=2x-30
2x+4y= -18
<em>Subtract 2x from both sides</em>
4y= -2x-18
<u>Combine equations:</u>
-2x-18=2x-30
<em>Add 2x to both sides</em>
-18=4x-30
<em>Add 30 to both sides</em>
12=4x
4x=12
<em>Divide both sides by 4</em>
x=3
Solving for y
x-2y=15
<em>Add 2y to both sides</em>
x=2y+15
<em>Multiply both sides by 2</em>
2x=4y+30
2x + 4y= -18
<em>Subtract 4y from both sides</em>
2x= -4y-18
<u>Combine equations:</u>
-4y-18=4y+30
<em>Add 4y to both sides</em>
-18=8y+30
<em>Subtract 30 from both sides</em>
8y= -48
<em>Divide both sides by 8</em>
y= -6
Answer: 50.27
Step-by-step explanation:
Area = pi r^2
= pi x 16
Answer:
31,41,51,71
Step-by-step explanation:
Answer:
77
Step-by-step explanation:
For each 2 evergreens there are 7 other trees.
Add 2 +7 = 9.
For each 7 non-evergreens there are 9 trees of all types.
The ratio of non-evergreens to total trees is 7/9.
Let x = number of non-evergreens.
7/9 = x/99
9x = 7 * 99
Divide both sides by 9.
x = 7 * 11
x = 77