Answer:
a = 5/39
Step-by-step explanation:
We assume you want to solve the equation for "a".
-2 = 4a -7 +35a . . . . simplify
5 = 39a . . . . . . . . . . add 7
5/39 = a . . . . . . . . . divide by the coefficient of a
It is in word form already
Sam's solution is incorrect. the correct answer is x=3
Let speed of the boat in still water = x miles per hour
Let speed of the current = y miles per hour
When water and current both flow in same direction then effective speed will be sum of both speeds that is (x+y)
now plug the given values in formula speed=distance/time
we get equation:
(x+y)=160/8
or x+y=20...(i)
When water and current both flow in opposite direction then effective speed will be difference of both speeds that is (x-y)
now plug the given values in formula speed=distance/time
we get equation:
(x-y)=160/40
or x-y=4
or x=4+y...(ii)
plug value of x into (i)
4+y+y=20
4+2y=20
2y=16
y=8
plug value of y into (ii)
x=4+8=12
Hence final answer is given by:
Speed of the boat in still water = 12 miles per hour
Speed of the current = 8 miles per hour
Answer:
24
Step-by-step explanation:
18/n = 21/28 You can cancel, but calculators make that unnecessary. Cross multiply
21n = 18 * 28
21n = 504 Divide by 21
n = 504 / 21
n = 24
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12/16 = n / 64 Cross Multiply
16n = 12 * 64
16n = 768 Divide by 16
n = 768/16
n = 48
