I am doing with Question Number 2
Let the two numbers be 'x' and 'y'.
According to the question, the product of two numbers is 14.
So, xy=14 (Equation 1)
Now, one of the numbers is 3 ½ times the other.
So, 
(Equation 2)
Substituting the value of 'x' from equation 2 in equation 1, we get
So, y= 2 and -2
So, 
and 
x=7 and -7
Numbers are 2,7 and -2,-7.
Sum of numbers 2 and 7 = 9
Sum of numbers -2 and -7 = -9.
Step-by-step explanation:
cross multiply all equations seperately
1,n=63
2.n=24
3.n=19
4.n=20
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.
