Answer:
The answer would be 1, whenever you square a negative number you should just input it as positive. The answer would be the same.
Step-by-step explanation:
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]
X=-3
because
-4x=21-9
-4x= 12 divide both sides
x=-3
Formula for volume of sphere V = 4/3 (Pi) r^3, where Pi ~ 3.14 and r is the radius = 7.
Therefore V = 4/3 * 3.14 * 7^3
= 4/3 * 3.14 * 343
= 4/3 * 1077.02
= 1,436.02667 cubic units