The speed of the current in a river is 6 miles per hour
<em><u>Solution:</u></em>
Given that,
Speed of boat in still water = 20 miles per hour
Time taken = 3 hours
Distance downstream = 78 miles
To find: Speed of current
<em><u>If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then: </u></em>
Speed downstream = (u + v) km/hr
Speed upstream = (u - v) km/hr
<em><u>Therefore, speed downstream is given as:</u></em>

We know that,
Speed downstream = (u + v)
26 = 20 + v
v = 26 - 20
v = 6 miles per hour
Thus speed of the current in a river is 6 miles per hour
Answer:
The graph crosses the x-axis at x = 0 and touches the x-axis at x = 3.
Step-by-step explanation:
When you graph this equation, you should see the zeros it passes and touches.
Answer:
The jeweler made 9 necklaces.
The jeweler made 8 bracelets.
Step-by-step explanation:
x = number of bracelets
y = number of necklaces
17 = x + y
238 = 5x + 22y
Make one of the coefficients, x, the same.
17 = x + y
Multiply this equation by 5.
85 = 5x + 5y
Subtract the equations to get rid of x.
(238 = 5x + 22y) - (85 = 5x + 5y)
(5x - 5x) + (22y - 5y) = 238 - 85
22y - 5y = 238 - 85
17y = 153
y = 153/17 = 9
The jeweler made 9 necklaces. Substitute this back into one of the equations to find x.
17 = x + y
17 = x + 9
17 - 9 = x
x = 8
238 = 5x + 22y
238 = 5x + 22(9)
238 = 5x + 198
238 - 198 = 5x
40 = 5x
x = 40/5
x = 8
The jeweler made 8 bracelets.
What you must do in this case is to find the roots of the polynomial.
We have then:
x ^ 2 + 20x + 100 = 36
Rewriting:
x ^ 2 + 20x + 64 = 0
The values of the roots are:
x1 = -4
x2 = -16
Remember that the values of the roots are what make the polinome zero
Answer:
x1 = -4
x2 = -16