Answer:
d. The cost of natural gas (y) = $0.83 per unit
Step-by-step explanation:
The explanation is shown below:-
the equation of system is:
750x + 17y = 141.61 (i)
300x + 30y =75.90 (ii)
as x indicates the cost of electricity and y indicates the costs of natural gas.
we will solve the both equation with the help of multiplication for (i) by 30 and for (ii) 75
![30\times (750x + 17y) 30\times 141.61\\\\](https://tex.z-dn.net/?f=30%5Ctimes%20%28750x%20%20%2B%2017y%29%2030%5Ctimes%20141.61%5C%5C%5C%5C)
after solve the above equation we will get
22,500x + 510y = 4248.3 (iii)
![75\times (330x + 30y) = 75\times 75.90](https://tex.z-dn.net/?f=75%5Ctimes%20%28330x%20%2B%2030y%29%20%3D%2075%5Ctimes%2075.90)
after solve the above equation we will get
22500x + 2250y = 5692.5 (iv)
After deducting the equation (iii) and (iv) we will get
1740 y = 1444.2
After Dividing by 15 both sides,
116y = 96.28
So, Katrina simplify the above system using linear equation and reach at the equation that is
116 y = 96.28
By Division property of equality defines that divide the equal no. of both sides of an equation:
by Division of 116 to both sides of an equation, to get y:
![\frac{116y}{116} = \frac{96.28}{116}](https://tex.z-dn.net/?f=%5Cfrac%7B116y%7D%7B116%7D%20%3D%20%5Cfrac%7B96.28%7D%7B116%7D)
y = 0.83
So, the natural gas is $0.83 per unit