Answer:
x(15) = 21 lb
Step-by-step explanation:
Rate of change in volume of salt water solution = rate of volume incoming - rate of volume outgoing
dV/dt = 4 - 2 =2gal/min
So, the equation for volume at cetain time t at given conditions and values becomes,
V(t) = 2t + V
V(t) = 2t + 20 gal-------------------euqation (1)
Rate of change in amount of salt = rate of salt in - rate of salt out
dx/dt = {0.5*4} - {[x(t)/V(t)]*2}
dx/dt = 2-2[(x(t))/(2t+20)]
dx/dt = 2-[(x(t))/(v(t))] lb/min
Now, with integrating factor, we get
exp[∫(1/(1+10))dt)] = t+10
the equation becomes
(t + 10)*x' + x = 2*(t+10)
((t+10)*x') = 2*(t+10)
(t+10)*x = t² + 20t + C
As x(0) = 0,
x(t) = (t²+20t)/(t+10)
x(15) = (15²+20*15)/(15+10)
x(15) = 21 lb
Answer:
72773100000%
Step-by-step explanation:
"Percent" means "per 100" or "over 100". So, to convert 727731000 to percent we rewrite 727731000 in terms of "per 100" or over 100.
Multiply 727731000 by 100/100. Since 100/100 = 1, we are only multiplying by 1 and not changing the value of our number.
7277310001×100100=72773100000100
72773100000/100 is 72773100000 over 100 and means 72773100000 per 100. 72773100000 "per 100" means 72773100000 "percent" or 72773100000%
Therefore, we have shown that
727731000 = 72773100000%
Simplified Conversion:
Multiply by 100 and add the percent sign %
727731000 × 100 becomes 72773100000%
Shortcut Conversion:
Move the decimal point 2 places to the right and add the percent sign %
727731000 becomes 72773100000%
Answer:
D: 1868
Step-by-step explanation:
43:20 ratio
43/20 = 2.15
869 * 2.15 = 1,868.35
round down to nearest whole number
1,868
Opposite number is like 8 and -8. And absolute value is like -8 and 8 or 9 and 9. The absolute value is always positive.
