Answer:
7
Step-by-step explanation:
you need to use PEMDAS
3 x 3 x 3 = 27 divided by 9 is 3 and 10-3=7
time * rate = distance
Downstream 4 * x = 4(x)
Upstream 6 * x - 2 = 6(x - 2)
distance downstream = distance upstream:
4(x) = 6(x - 2)
4x = 6x - 12
-2x = -12
x = 6
Distance Upstream: 4x = 4(6) = 24
Distance Upstream: 6(x - 2) = 6(6 - 2) = 6(4) = 24
Total distance traveled is Upstream + Downstream = 24 + 24 = 48
Answer: 48 miles
Answer:
2(5+y)+2y=38 10+2y+2y=38 4y=28 y=7 i think
Step-by-step explanation:
If you mean how do you get x by it's you divide both sides by 8, to cancel out the multiplication between x and 8, meaning that it would end up being x=7, sorry if that didn't answer your question correctly.
Answer:
20 hours
Step-by-step explanation:
We can work easier if we think in terms of an hour
the first equation that we can write is
A + B = 1/4 (its meaning is that in an hour A and B fill 1/4 of the cistern)
the second equation we can write is
A + C = 1/5 (its meaning is that in an hour A and C fill 1/5 of the cistern)
the third equation that we can write is
B = 2C (its meaning is that in an hour B fill 2 times C the cistern)
now we can substitute the value of B in the first two equations
A + 2C = 1/4
A + C = 1/5
A = 1/5 - C
1/5 - C + 2C = 1/4
C = 1/4 -1/5
C = (5-4)/20
C = 1/20 (this means that in an hour C will fill 1/20 of the cistern, so it takes 20 hours to fill the entire cistern)
A = 1/5 - 1/20
A = (4-1)/20 = 3/20
B = 1/20 *2 = 1/10
