Answer:
D) x = 4, y = -2, z = 3
Step-by-step explanation:
x = 3z − 5
2x + 2z = y + 16
2(3z - 5) + 2z = y + 16
6z - 10 + 2z = y + 16
8z = y + 26 ---> (A)
7x − 5z = 3y + 19
7(3z - 5) - 5z = 3y + 19
21z - 35 - 5z = 3y + 19
16z = 3y + 54 ---> (B)
8z = y + 26
16z = 3y + 54
2(y + 26) = 3y + 54
2y + 52 = 3y + 54
y = -2
8z = -2 + 26
8z = 24
z = 3
x = 3(3) - 5
x = 4
Answer:
J 8.5 >=2.5p
Step-by-step explanation:
To do this plug in 3.4 for each version of p. The only one that would be true would be J.
Answer:
b
Step-by-step explanation:
Answer: the cost per unit of gas is $0.28
Step-by-step explanation:
Let x represent the cost per unit of electricity.
Let y represent the cost per unit of gas.
During one month, a homeowner used 500 units of electricity and 100 units of gas for a total cost of $333. This is expressed as
500x + 100y = 333 - - - -- - -- - -- -1
The next month, 400 units of electricity and 150 units of gas were used for a total cost of $286. This is expressed as
400x + 150y = 286 - - - - - - - - - --2
Multiplying equation 1 by 400 and equation 2 by 500, it becomes
200000x + 40000y = 133200
200000x + 75000y = 143000
Subtracting, it becomes
- 35000y = - 9800
y = - 9800/- 35000
y = 0.28
Substituting y = 0.28 into equation 2, it becomes
400x + 150 × 0.28 = 286
400x = 286 - 42 = 244
x = 244/400 = 0.61
