Answer:
Step-by-step explanation:So we know x + y = 21 and 5x +10y = 165 We line them up in columns x + y = 21 5x +10y = 165 To eliminate the x variable, I'll multiply every element in the 1st equation by -5. -5x + -5y = -105 5x + 10y = 165 Now we combine (add) the equations, which eliminates x altogether. 5y = 60 ... y = 12 From there, x + 12 = 21 ... x = 21-12 ... x = 9 You should double check. Do 9 nickles and 12 dimes equal $1.65? A very important thing to remember using this method is to do the same thing to each element in the equation that you change! I hope that helps.
Answer:
48
Step-by-step explanation:
Answer:


Step-by-step explanation:
The given system is
3x-2y=6
0.4(20y+15)=x
The slope intercept form is y=mx+c.
For the first equation, 3x-2y=6, we add -3x to both side -2y=-3x+6

For 0.4(20y+15)=x, we expand to get:


Divide through by 8

Therefore the system in slope-intercept form is:


Summary of problem.
annual production = 60000 units
work hours per worker = 200*12=2400 hours
productivity = 0.15 unit / person-hour
Need to calculate the number of workers/persons employed.
Each unit requires 1 unit / 0.15 unit/person-hour
= 1/0.15 person-hours / unit
60000 unit requires 60000 units * 1/0.15 person-hours/unit
= 400000 person-hours
400000 person-hours requires 400000 person-hours /2400 hours = 166.7 persons
=>
The plant has 167 labourers (assuming perfect attendance).
Answer: F=140
Step-by-step explanation:
720=(x-60)+(x-40)+(x-20)+130+120+110
720-130-120-110=3x-120
360=3x-120
360+120=3x
480=3x
480/3=x
160=x
F=160-20
Next problem
102+31+x=180
133+x=180
x=180-133
x=47