Choo kheng must travel at least 288 kilometers in a submarine in order to reach her destination. let s represent the number of hours the submarine can travel on the water's surface and u uu represent the number of hours it can travel underwater in order to reach choo kheng's destination. 3 6 s + 6 4 u ≥ 2 8 8 36s+64u≥28836, s, plus, 64, u, is greater than or equal to, 288 the submarine travels for 2 2/3 start fraction, 2, divided by, 3, end fraction hours on the water's surface. what is the least number of hours the submarine must travel underwater in order for choo kheng to reach her destination?

U = 3 hours since 3 is the least amount of time it would take underwater. Hope this helped

The least number of hours the submarine must travel underwater is 3.

Step-by-step explanation:

Given inequality,

36S + 64U ≥ 288,

Where, S represents the number of hours the submarine can travel on the water's surface,

U represents the number of hours it can travel underwater in order to reach Choo Kheng's destination,

Given,

The submarine travels for hours on the water's surface,

That is, S =

By substituting the value,

Hence, the least value of U is 3,

That is, the least number of hours the submarine must travel underwater is 3.

  5.   y=6; de=7; fg=8

  6.   x=4.2; jl=14.2; mn=13

step-by-step explanation:

when chords cross inside a circle, the product of the segment lengths is a constant.

5. dh×eh = fh×gh

  y = gh = dh×eh/fh = 3×4/2 . . . divide by the coefficient of gh

  y = 6

of course, the total chord length is the sum of the lengths of its segments.

  de = dh +eh = 3+4 = 7

  fg = fh +gh = 2+6 = 8

6. this problem works the same way as the previous one.

  x = lk = mk×nk/jk = 6×7/10 = 4.2

  jl = jk +lk = 10 +4.2 = 14.2

  mn = mk +nk = 6 +7 = 13

comment on chords and secants

you can think of the points h (problem 5) and k (problem 6) as points where the chords meet. a chord is part of a secant line, a line that intersects the circle in two points. one can also consider these points (h or k) to be the points where the respective secant lines meet.

then, the product that is a constant is the product of the distance from the meeting point (h or k) to one circle intersection with the distance from that meeting point to the other circle intersection. for problem 5, the constant is the product hd×he = hf×hg.

it turns out that this rule regarding the products of lengths to points of intersection is also true when the secants intersect outside the circle.

that is, you only need to remember one rule to work both kinds of problems.

idk sry

step-by-step explanation: