Option 1, 2, & 4 are irrational numbers
Isolate the x in both cases. What you do to one side, you do to the other.
11x + 4 < 15
Subtract 4 from both sides
11x + 4 (-4) < 15 (-4)
11x < 11
isolate the x, divide 11 from both sides
11x/11 < 11/11
x< 1
x < 1 is your answer for the first one
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Again, isolate the x.
12x - 7 > -25
Add 7 to both sides
12x - 7 (+7) > -25 (+7)
12x > -18
Isolate the x, divide 12 from both sides
12x/12 > -18/12
x > -1.5 is your answer for the second one.
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hope this helps
Let the speed of the current equal c
and the speed of the boat in still water equal b.
b + c = 1.5 (b - c)
b + c = 1.5b - 1.5c
0.5b = 2.5c
b = 5c
The speed of the current is 1.5 mph so
b = 5 * 1.5 = 7.5 mph
