Answer:
Explanation:
12b + 1 5c = 420
b ---> number of hour baby sitting
c-----> number of hours cleaning
c = 32 hours
Plugin c = 32 in the equation,
12b + 15*32 = 420
12b + 480 = 420
Subtract 480 from both sides
12 b = 420 - 480
12b = -60
So, This is not a reasonable value.
2) b = 10 hours
Plugin b = 10 hours
12*10 + 15c = 420
120 + 15c = 420
15c = 420 - 120
15c = 300
Divide both sides by 15
c = 300/15
c = 20 hours
He has to do cleaning for 20 hours
Yes, It is reasonable value