Answer:
9
Step-by-step explanation: did it
1. To solve this exercise, you must make a system of equations.
2. You have that f<span>our times a number minus twice another number is -8:
</span>
4x-2y=-8
3. And t<span>he sum of the two number is 19:
</span>
x+y=19
4. As you can see, you have two equations:
4x-2y=-8 (i)
x+y=19 (ii)
5. Let's clear the "x" from the equation (ii):
x=19-y
6. Now, you need to susbtitute x=19-y into the equation (i):
4x-2y=-8
4(19-y)-2y=-8
76-4y-2y=-8
76-6y=-8
-6y=-8-76
-6y=-84
y=-84/-6
y=14
7. You must susbstitute y=14 into the equation (ii) and clear "x":
x+y=19
x+14=19
x=19-14
x=5
The answer is: 5 and 14
Answer: r<-2
Step-by-step explanation:
-3(r-5)+7>28
-3(r-5)+7-7>28-7
-3(r-5)>21
3(r-5)/3 < -21/3
r-5<-7
r-5+5<-7+5
r<-2
Answer: 125.80 ft
Step-by-step explanation:
Asuming the described situation is as shown in the figure below, we need to find the distance 
between the kite and Jacks house, but first we need to find the 
, 
and then 
.
How?
We will use trigonometry, especifically the trigonometric functions sine and cosine:
For :
(1)
Where is the opposite side to the angle and 
the hypotenuse.
Isolating :
(2)
For :
(3)
Where is the adjacent side to the angle.
Isolating :
(4)
Finding :
(5)
(6)
Now that we have found these values, we have to work with a bigger triangle, where the hypotenuse is the distance between the kite and Jack's house and the sides are the values calculated in (4) and (6).
So, in this case we will use the <u>Pithagorean theorem</u>:
(7)
Isolating and writing with the known values:
(8)
(9)
This is the distance between the kite and the house
