Answer:
- 12. x = 6, side = 83
- 13. x = 18, side = 29
- 14. x = 11, sides = 74, 74 and 37
- 15. x = 23, sides = 95, 95 and 108
Step-by-step explanation:
<em>11 is incomplete, can't solve</em>
12
<u>The triangle is equilateral, so all sides are equal, using one pair to find x:</u>
- 13x + 5 = 17x - 19
- 17x - 13x = 5 + 19
- 4x = 24
- x = 6
<u>Each side is:</u>
13.
<u>Sides are equal as triangle is equilateral</u>
- QR = 2x - 7
- RS = 5x - 61
- QS = x + 11
<u>Finding x by comparing two sides</u>
- 2x - 7 = 5x - 61
- 5x - 2x = 61 - 7
- 3x = 54
- x = 18
<u>Sides are equal</u>
14.
<u>Equal sides of isosceles triangle:</u>
- CD = DE
- 9x - 25 = 6x + 8
- 9x - 6x = 8 + 25
- 3x = 33
- x = 11
<u>Sides are</u>
- CD = DE = 9*11 - 25 = 99 - 25 = 74
- CE = 10*11 - 73 = 110 - 73 = 37
15.
<u>Equal sides of isosceles triangle WXY, WX = WY</u>
- WX = 4x + 3
- WY = 7x - 66
- XY = 5x - 7
- 4x + 3 = 7x - 66
- 7x - 4x = 3 + 66
- 3x = 69
- x = 23
<u>Sides are:</u>
- WX=WY = 4*23 + 3 = 95
- XY = 5*23 - 7 = 108
The smallest region that can be photographed is
5*7 = 35 square km
so we want to know how long it takes to zoom out to an area of
35 * 5 = 175 square km.
Notice that the length and width increase at the same rate, 2 km/sec, and they start out with a difference of two, so when the width has increased from 5 to x, the length will have increased from 7 to x+2. At the desired coverage area, then,
x(x+2) = 175
x^2 + 2x = 175
x^2 + 2x + 1 = 176 [completing the square]
(x+1)^2 = 176
x+1 = ±4√11
x = -1 ±4√11
Since a negative value for x is meaningless here, x must be
-1 + 4√11 = about 12.27 km
and the time it took to increast to that value was
(12.27 - 5) km / (2 km/sec) = about 3.63 seconds
10^9 (Ten to the power of nine)
Answer:
BC is just 3d+7??
Step-by-step explanation:
Answer:
False
Step-by-step explanation:
You substitute 
for the second equation.
Then you have to distribute 
.
Combine like terms.
