Speed of the boat = u
speed of the current = v
in downstream,
u - v = 105/5
u - v = 21
in upstream
u + v = 105/7
u + v = 15
add both equations
2u = 36
u = 18
v = -3
so
speed of the boat = 18 km/h
speed of the current = 3 km/h
X^3 / X^5 = X^ -2
you have to subtract the exponents when you’re dividing
Answer:
Width=37in
Length=55in
Step-by-step explanation:
Let x in be the width dimension, the length dimension will be x+18 in. Area of a rectangle is calculated as A=lw. Given the area as2143 sq in, x can be calculated as:

#Substitute for every x in our function to find the true value of x:
#l=37+18=55in
for x=38:
#l=38+18=56in
For x=39:
#l=39+1854in
From the calculations above, A television with a width of 37 in and length 55in has its area closest to 2143 sq in.