Answer with Step-by-step explanation:
We are given that

For each real number 
To prove that f is one -to-one.
Proof:Let
and
be any nonzero real numbers such that

By using the definition of f to rewrite the left hand side of this equation

Then, by using the definition of f to rewrite the right hand side of this equation of 

Equating the expression then we get




Therefore, f is one-to-one.
The answer is 2z+3. The like terms are 5z and -3z so you can subtract them and get 2z. Thus, the answer is 2z+3
234 - 3 = 231
231 : 3 = 77
77 + 1 =78
78 + 1 = 79
------------------------
77 78 79
77+78+79= 234
Answer: each girl received 30 stickers.
Step-by-step explanation:
Let x represent the number of stickers that the boys received.
Let y represent the number of stickers that the girls received.
The total number of children was 42. 2/3 of the children were boys. It means that the number of boys were
2/3 × 42 = 28
The number if girls would be
42 - 28 = 14
The total number of stickers that the school principal shared was 840. It means that
28x + 14y = 840- - - - - - - - -1
Each of the boys received the same number of stickers while each girl received twice as many as each boy. It means that
y = 2x
Substituting y = 2x into equation 1, it becomes
28x + 14 × 2x = 840
28x + 28x = 840
56x = 840
x = 840/56
x = 15
y = 2x = 15 × 2
y = 30
I am probably wrong but with the math I do I got 35