Answer:
15 black water bottles
Step-by-step explanation:
let w represent white water bottles, and let b represent black water bottles.
set up a system of equations:
w+b=20
w+2b=35
(the top equation shows that the number of white water bottles he sold and the number of black water bottles he sold equals to 20, since it says that the total number of water bottles is 20. the bottom equation shows that white water bottles cost $1, and black water bottles cost $2, and that the total amount of money he got from selling them is $35).
in the top equation, isolate w:
w+b=20
w=20-b
now we do substitution. in the bottom equation, substitute 20-b for w:
w+2b=35
20-b+2b=35
then, solve:
b+20=35
b=15
this means that he sold 15 black water bottles.
Answer:
x = 7.5
Step-by-step explanation:
4 = 2/3 (2x - 9)
4 = 4/3x - 6
4 + 6 = 4/3x - 6 + 6
10 = 4/3x
10 x 3/4 = x
x = 7.5
Answer:
22
Step-by-step explanation:
QS =2×11 = 22
__________
7(2y+1)+3y
14y + 7 + 3y
17y + 7
Answer:
C, 3y(2y+9)
Step-by-step explanation:
you can factor out a 3 from both 6 and 27, as well as a y from both so you would put them on the outside as shown in C. Hope that helped! Let me know if you need more of an explanation, and id be happy to help!
6y^2+27y
6 and 27 both have a common factor, meaning that the same number can go in to them both, 3. Because both 6 and 27 have a y, you are able to also take out a y so outside would be 3y.
so the answer is 3y(2y+9)
