4x-10=6x+4; -10=2x+4; -14=2x; x=-7
Answer:
If I am understanding your question, the total upstream is 8 miles and another 8 miles downstream.
Let s = the speed of the boat in still water
d = rt
8 = 5(s + 3) downstream
8 = 5s + 15 equation 1
8 = 5(s - 3) upstream
8 = 5s - 15 Add equation 1
8 = 5s + 15
16 = 10s Divide both sides by 10.
s = 16/10 = 8/5 = 1.6 mph
Answer:
a + b = 5
Step-by-step explanation:
To solve this system of equations, we can use a strategy called elimination, which is when we get rid of a variable by adding/subtracting two equations.
Firstly, we want to make sure the absolute value of the coefficients that equal.
Lets eliminate b:
4a + 6b = 24
Multiply both sides by 2:
8a + 12b = 48
We also have:
6a - 12b = -6.
Now lets add that with
8a + 12b = 48
-> 6a + 8a + 12b - 12b = 48 -6
-> 14a = 42
-> a = 3
Now that we know a, lets plug it into one of our original equations:
4(3) + 6b = 24
12 + 6b = 24
6b = 12
b = 2
Finally, add the two values we found:
a+b = 2+3= 5
Answer:490pi
Step-by-step explanation:just trust me
