no se que decir pero usted sabe ispañol
X=number of boys in the club at first
y=number of girls in the club at first.
(x+y) = members were in the club at first.
We can suggest the next system of equation.
x/y=1/2 ⇒ x=y/2
(x+5)/y=3/4 ⇒4(x+5)=3y
Finally, we have the next system of equations:
x=y/2
4(x+5)=3y
We are going to solve by substitution method.
4(y/2 + 5)=3y
2y+20=3y
2y-3y=-20
-y=-20
y=20
x=y/2
x=20/2
x=10
(x+y)=10+20=30
Answer: There were 30 members int the club at first, they were 10 boys and 20 girls.
The original number is 7 i think.
10(x^2) = 70x
10x^2 - 70x = 0
x^2 -7x =0
Δ= b^2 -4ac
where c doesnt exist=0
Δ= 49
-b ± √Δ /2a
7 ± √49 /2
7±7/2
x is either 14/2= 7
or 1/2, which doesnt work.
Lets see:
10(7^2) = 70•7
10•49 = 490
and that is right.
i hope my logic is correct.
We need to expand and add the formula
![5n + 2](https://tex.z-dn.net/?f=5n%20%2B%202)
from 3 to 6, inclusive.
![5(3) + 2 \\ 5(4) + 2 \\ 5(5) + 2 \\ 5(6) + 2](https://tex.z-dn.net/?f=5%283%29%20%2B%202%20%5C%5C%205%284%29%20%2B%202%20%5C%5C%205%285%29%20%2B%202%20%5C%5C%205%286%29%20%2B%202)
which is equal to
![15 + 2 = 17 \\ 20 + 2 = 22 \\ 25 + 2 = 27 \\ 30 + 2 = 32](https://tex.z-dn.net/?f=15%20%2B%202%20%3D%2017%20%5C%5C%2020%20%2B%202%20%3D%2022%20%5C%5C%2025%20%2B%202%20%3D%2027%20%5C%5C%2030%20%2B%202%20%3D%2032)
The answer is D. 17 + 22 + 27 + 32
Answer:
52 miles per hour
Step-by-step explanation:
The speed of the car can be found by dividing the distance by the time. THe distance is 117 miles and the time is 2 1/4 hours or 2.25 hours.
![s=\frac{d}{t} \\s=\frac{117}{2.25} \\s= 52](https://tex.z-dn.net/?f=s%3D%5Cfrac%7Bd%7D%7Bt%7D%20%5C%5Cs%3D%5Cfrac%7B117%7D%7B2.25%7D%20%5C%5Cs%3D%2052)