3r+n2−r+5−2n+2<span />=3r+n2+−r+5+−2n+2=3r+n2+−r+5+−2n+2<span />=(n2)+(−2n)+(3r+−r)+(5+2)<span />=n2+−2n+2r+7<span /><span />
=n2−2n+2r+7
Answer:
The second one is correct.
Answer:
Make -3 a fraction
Step-by-step explanation:
3/4 x -3
3/4 x -3/1
3/4 x -12/4
-72/4 = 18
Answer:
Speed of the river =
km per hour
Step-by-step explanation:
Speed of the boat in still water = 4 km per hour
Let the speed of the river = v km per hour
Speed of the boat upstream = (4 - v) km per hour
Time taken to cover 6 km = 
=
hours
Speed of the boat downstream = (4 + v) km per hour
Time taken to cover 12 km =
hours
Since, time taken by the boat in both the cases is same,

6(4 + v) = 12(4 - v)
24 + 6v = 48 - 12v
12v + 6v = 48 - 24
18v = 24
v = 
v =
km per hour