I think the correct answer from the choices listed above is option C. <span>Two lines are perpendicular, and neither line is horizontal so it must be that the slopes of the lines are opposite reciprocals, one slope is positive and the other has a negative slope. Having different slopes so they should intersect the y-axis at different values.</span>
Let, the speed of boat = x
Speed of current = y
So, x + y = 280/7
x + y = 40 ---- first equation
x - y = 280/14
x - y = 20
x = 20 + y
Substitute this value of x in first equation,
20 + y + y = 40
2y = 40 - 20
y = 20/2
y = 10
Substitute this in first equation,
x + 10 = 40
x = 30
In short, Speed of Boat = 30 mph, & speed of current = 10 mph
Hope this helps!
Ln(x) should be the answer
Answer:
B. 4x ≤ 320
Step-by-step explanation:
Not sure how to explain my thinking. However, 4x must be smaller than 320 because she cannot spend more than that.
