Answer:
12
Step-by-step explanation:
Factors of 30: 1,2,3,5,(6),10,15,30
Factors of 42: 1,2,3,(6),7,14,21,42
30 divided by 6, 42 divided by 6
(5) + (7)= 12
Speed, S = Distance (d) / Time (t) => S= d/t => t= d/S
Let the speed of boat in still water be x mph
Resulting speed upstream = x-4 mph for a distance of 30 miles
Resulting speed downstream = x-4 mph for a distance of 50 miles
Time taken in both distances is equal.
Therefore,
30/(x-4) = 50/(x+4) => 30(x+4) = 50(x-4) => 30x+120 = 50x-200 => 120+200 = (50-30)x => 20x = 320 => x=320/20 = 16 mph
The speed of boat in still water is 16 mph.
Must be
(c) 12.11.10
Or
(d) 12
Answer:
Step-by-step explanation:
536 because it is correct
The lines are
i) y=-x+6
ii) y=2x-3
The solution of the system of equations is found by equalizing the 2 equations:
-x+6=2x-3
-2x-x=-6-3
-3x=-9
x=-9/(-3)=3
substitute x=3 in either i) or ii):
i) y=-3+6=3
ii) y=2(3)-3=6-3=3
(the result is the same, so checking one is enough)
This means that the point (3, 3) is a point which is in both lines, so a solution to the system.
In graphs, this means that the lines intersect at (3, 3) ONLY
Answer: The graph where the lines intersect at (3, 3)
