D is the one that is rounded incorrectly.
It should've been rounded up to 13.8 not down to 13.7
I just need points honestly sorry have a good one thank you
Answer:
Step-by-step explanation:
the answer is 130
Answer:
3
Step-by-step explanation:
step1 Isolate the square root on the left hand side
Original equation
√2x-5-4 = -x
Isolate
√2x-5 = 4-x
step2 eliminate the radical on the left hand side
Raise both sides to the second power
(√2x-5)2 = (4-x)2
After squaring
2x-5 = x2-8x+16
step3 Solve the quadratic equation
Rearranged equation
x2 - 10x + 21 = 0
This equation has two rational roots:
{x1, x2}={7, 3}
step4 Check that the first solution is correct
Original equation, root isolated
√2x-5 = 4-x
Plug in 7 for x
√2•(7)-5 = 4-(7)
Simplify
√9 = -3
Solution does not check
3 ≠ -3
step5 Check that the second solution is correct
Original equation, root isolated
√2x-5 = 4-x
Plug in 3 for x
√2•(3)-5 = 4-(3)
Simplify
√1 = 1
Solution checks !!
Solution is:
x = 3
Let the boat speed in still water be b.
Let the current speed be c.
The speed going upstream is 20/4 = 5 mph.
The speed going downstream is 32/4 = 8 mph.
b - c = 5 ........(1)
b + c = 8 .......(2)
Adding equations (1) and (2) we get:
2b = 13
b = 13/2 = 6.5
Plugging in the value for b into equation (1) we find c = 1.5.
The boat speed in still water is 6.5 mph and the current speed is 1.5 mph.
