What is the answer to these word problems? Alg II?

Question

I just can't seem to solve these. Any help is appreciated!

1. K and L start 400 km apart and approach each other at constant but different rates. It takes 12 hours for them to meet. If K goes 10 km per hour faster than L what are their rates?

2. Earl Wells leases a rectangular tract of land. 5.3 km by 4.1 k. He acn drill for oil on the inner 70% of the land, but must leave a uniform width around edge with no wells. What is the width of the strip.

Answer 1

1)  Rate times time equals distance.  Let the rate of L be v.  The rate of K will be v + 10.  Together, they travel 400 km in 12 hours, so

(v + v + 10)(12) = 400

You should be able to solve that easily.

2)  The total area will be (5.3 km)(4.1 km).  Take 70% of that - that's the area of the inner rectangle.  Let x be the width of the strip.  The dimensions of the inner strip will be 5.3 - 2x by 4.1 - 2x.  You should be able to tell me why it's 2x.  If you have trouble seeing it, draw a diagram.  So,  (5.3 - 2x)(4.1 - 2x) equals 70% of the original area.

Just out of curiosity, what was it about these problems that gave you trouble?