19/40 as a fraction and decimal it is 0.475
Answer:
2.8a²+0.9a - 1.2
Step-by-step explanation:
Given the expression 0.3(3a-4)-0.05(8a)(-7a)
Expand using the distributive law
0.3(3a-4)-0.05(8a)(-7a)
0.3(3a)-0.3(4)-0.05(8a)(-7a)
0.9a-1.2 - 0.05(8a)(-7a)
0.9a - 1.2 + 2.8a²
Rearrange
2.8a²+0.9a - 1.2
Hence the required expression is 2.8a²+0.9a - 1.2
4x / 5 = 1 / 3 ( 2x - 15 )
4x / 5= ( 2x - 15 ) / 3
4x × 3 = 5 ( 2x - 15 )
12x = 10x - 75
12x - 10x = - 75
2x = - 75
x = - 75 / 2
x = - 37.5
So 2 gallons every 5 minutes
2/5= .4
so .4 a minute
and you already have 5 gallons in so those need to be added
m=minutes
y=0.4m + 5 will be what you want to find out if you are looking to find out how much will be there in a certain time
for 50 minutes you will have
y=0.4(50) +5
20+5
25 gallons
HOWEVER, the equation has to be changed if you want to tell how long you have to wait for it to fill.
m=2.5(g-5)
m=minutes
g= gallons
you subtract 5 because they are already there
you multiply by 2.5 because it fills at a rate of 1 gallon every 2.5 minutes.
m=2.5(1500-5)
for the sake of it being easier i will do the -5 separately
2.5(1500 = 3750
2.5(-5= -12.5
3750-12.5
3737.5 minutes to fill the pool.
3720/60 = 62
17.5/60 = .292
62.292 hours to fill the pool.
p.s. you have a really slow hose.
Its good you didn't wait for it to fill, you would have died from lack of water before then if you just sat and waited.
<span />
