I'm not sure I understand the question. Is this worded correctly?
2.1x + 4.2y = 14.7 is the same as x + 2y = 7 (divide both sides by 2.1)
-5.7x-1.9y=-11.4 is the same as 3x + y = 6 (divide both sides by -1.9)
Rearrange the first equation to get x = 7 - 2y and substitute into the second equation, 3(7 - 2y) + y = 6, 21 - 6y + y = 6, 5y = 15, y = 3
Substitute y = 3 into the first equation x + 2(3) = 7, x = 1
x = 1 and y = 3
Notice that we have common denominator 2, so we can split the denominator to express the function in the form

where

is the slope

is the y-intercept


Look what we have here, a linear function! We know that the domain and range of linear functions is the real numbers.
We can conclude that:
the domain of the function is
all the real numbers
the range of the function
is all the real numbers
Now, to find the inverse of our function, we are going to replace

with

; then, we are going to interchange

and

and solve for

:







The inverse of our linear function, is another linear function, so we can conclude that:
the domain of the inverse function is
all the real numbers
the range of the inverse function
is all the real numbers
Answer:
6 cm by 17 cm
Step-by-step explanation:
The area is the product of the dimensions; the perimeter is double the sum of the dimensions.
So, we want to find two numbers whose product is 102 and whose sum is 23.
102 = 1·102 = 2·51 = 3·34 = 6·17
The last of these factor pairs has a sum of 23.
The dimensions are 6 cm by 17 cm.