You have two unknown rates, so we need to develop two equations to solve for these unknowns (based on the information given on the problem statement):
5x + 10y = 725
x + y = 100
By substitution, we get:
5x + 10(100 - x) = 725
5x + 1000 - 10x = 725
-5x = 725 - 1000
-5x = -275
x = -275/-5 = 55
100 - 55 = 45
Thus:
The mechanic who worked for 5 hours charged his time at $55/hr, and the mechanic who worked for 10 hours charged his time at $45/hr.
To verify, plug and chug the results back into the original equations:
5(55) + 10(45) = 725
275 + 450 = 725
725 = 725 [OK]
55 + 45 = 100 [OK]
<u>To make this problem solvable, I have replaced the 't' in the second equation for a 'y'.</u>
Answer:
<em>x = -9</em>
<em>y = 2</em>
Step-by-step explanation:
<u>Solve the system:</u>
2x + 3y = -12 [1]
2x + y = -16 [2]
Subtracting [1] and [2]:
3y - y = -12 + 16
2y = 4
y = 4/2 = 2
From [1]:
2x + 3(2) = -12
2x + 6 = -12
2x = -18
x = -18/2 = -9
Solution:
x = -9
y = 2
Answer:

Step-by-step explanation:
Total number of tickets sold = 3388
Total number of coach tickets = 3069
Total number of first-class tickets = Total number of tickets sold - Total number of coach tickets
= 3388 - 3069
= 319

Ratio of the number of first-class tickets to the total number of tickets = 319:3388
Answer:The particles in a solid are tightly packed and locked in place. Although we cannot see it or feel it, the particles are moving = vibrating in place.
Answer: None of the above
Step-by-step explanation: Because none of them will equal the solution which is 0.5,
1.7 + (-1.2) = 0.5