For the answer to the question above,
First, let's make the equation,
(1/6) + (1/x) = 1/(3/2) = (2/3) = (4/6)
then
1/x = (3/6) = (1/2)
so the answer would be
x = 2
It will take 2 hours take<span> your friend's pump to empty the pool when working alone? </span>
X+y=-1
3x-y=21
add them equations
x+y=-1
<u>3x-y=21 +</u>
4x+0y=20
4x=20
divide by 4
x=5
x+y=-1
5+y=-1
minus 5 both sides
y=-6
(x,y)
(5,-6)
D is answer
Mass = density* volume
since density= mass/volume then mass/volume*volume=mass
= 4.5*0.4 = 1.80g