Answer:
![\sf \text{The numbers are $\dfrac{-14}{3} $ and $\dfrac{-7}{3}$}](https://tex.z-dn.net/?f=%5Csf%20%5Ctext%7BThe%20numbers%20are%20%24%5Cdfrac%7B-14%7D%7B3%7D%20%24%20and%20%24%5Cdfrac%7B-7%7D%7B3%7D%24%7D)
Step-by-step explanation:
Let the numbers be x , y
Sum of two numers = -7
x + y = -7------------(I)
Two times the first number equals 4 the second number.
2x = 4y ----------(II)
Divide both sides by 2
![\sf \dfrac{2x}{2}=\dfrac{4y}{2}](https://tex.z-dn.net/?f=%5Csf%20%5Cdfrac%7B2x%7D%7B2%7D%3D%5Cdfrac%7B4y%7D%7B2%7D)
x = 2y
Subtitute x = 2y in equation (I)
2y + y = -7
3y = -7
y = -7/3
Plugin y = -7/3 in equation (II)
![\sf 2x = 4*\dfrac{-7}{3}\\\\2x = \dfrac{-28}{3}\\\\x =\dfrac{-28}{3*2}\\\\x = \dfrac{-14}{3}](https://tex.z-dn.net/?f=%5Csf%202x%20%3D%204%2A%5Cdfrac%7B-7%7D%7B3%7D%5C%5C%5C%5C2x%20%3D%20%5Cdfrac%7B-28%7D%7B3%7D%5C%5C%5C%5Cx%20%3D%5Cdfrac%7B-28%7D%7B3%2A2%7D%5C%5C%5C%5Cx%20%3D%20%5Cdfrac%7B-14%7D%7B3%7D)
Answer:
$(a + b) + cn cent
Step-by-step explanation:
Given :
Fixed charge = $a
Rent of a meter = $b
Charge per unit of electricity = c cents
The total cost of using n units of electricity :
For n units of electricity ;
Fixed charge is paid once
Meter rent is paid once
The cost of electricity = (number of units * cost per unit) = (n * c) = nc cents
Total cost of n units of electricity :
$(a + b) + cn cent
The number of yards is 21. 21 times 3 is 63.
The answer is D my Friend