This is a simultaneous question.
To solve this, we have to make up 2 equations based on the info provided like so:
electricity = e
gas = g
600e + 100g = $412 ——(1)
400e + 150g = $293 ——(2)
In this case, it’ll be easier to use the elimination method where you eliminate a variable so you can calculate only one.
Here, we will be eliminating e so we can get the cost of gas.
To do this we need to get both equation’s e to 600, so we have to multiply equation 2 by 1.5:
(2) x 1.5:
400e + 150g = $293
600e + 225g = $439.50 ——(3)
Now we eliminate e by subtracting equation 1 from equation 3:
(3) - (1):
600e + 225g - 600e - 100g = $439.50 -$412
125g = $27.50
g = $0.22.
Therefore one unit of gas costs $0.22.
Hope it helps and have a good day ahead :D
Answer:...................:)
Step-by-step explanation:
C + d = 2(c - d)
c = 9
9 + d = 2(9 - d)
9 + d = 18 - 2d
d + 2d = 18 - 9
3d = 9
d = 9/3
d = 3 <=== daira is 3 when carl is 9 years old and older then she
if carl is 9 years old and is younger then she ...I dont really understand this question....carl is 9 and daira is 3......possibly...their is a difference of 6 years in their ages....so if carl is 9 and younger then she, the daira is 6 years older ?? making her 9 + 6 = 15....not sure about this one ....the whole question throws me off