Let 'x' be the distance from THE far bank where 700 is the distance to the NEAR bank
boat one has travelled 700 (rate = 700/unit time) boat two has travelled x rate = x / unit time
boat one then travels x + 400 more and boat two travels 700 + (700+x -400) more when they meet
The time is the same rate x time = distance distance/rate = time equate the distances divided by the respective rates
(700 + x + 400)/700 = ( x + 700 + (700+x-400) )/x
1100x + x^2 = 1400x + 700000
x^2-300x -700000 = 0 quadratic formula yields x = 1000
One boat travels 700 the other 1000 whe they first meet.....width of river = 700+ 1000 = 1700 m
D
They are the same length :)
1/10=x hope that helps a bunch
We can reject the last one: subtracting a non-zero value will result in a smaller value.
So now we have:
<span>2(A + B)
(A + B)2
A2 + B2
If all of them are mulptiplications, then they are all equivalent!
I mean by this, if what you meant is this:
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<span>2*(A + B)
(A + B)*2
A*2 + B*2
If there is no sign, then the multiplication sign is implicit,
and all of these expressions say exactly the same: two of A and two of B.
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