Answer:
(cos^2 y) /(1-sin y) = (1 - sin^2 y) / (1-sin y) = ((1-sin y)(1+sin y)) / (1-sin y) = 1+sin y
R=7/5
You can list two equations:
2s+10r=42 and 4s-10r=42.
Then try to delete S, you will get r
It is 0.525 that is what it is
<span><span><span><span><span><span><span><span><span><span><span>2<span>y2</span></span>−<span>7y</span></span>−<span><span><span>153</span></span><span>y2</span></span></span>−<span>8y</span></span>−<span>29<span>y2</span></span></span>−<span><span><span>14</span></span><span>y2</span></span></span>−<span><span><span>9<span>y2</span></span></span></span></span>+<span>3y</span></span>−<span><span><span>102</span></span><span>y2</span></span></span>−<span>9y</span></span>+9</span><span>=<span><span><span><span><span><span><span><span><span><span>−149</span>4</span></span><span>y4</span></span>−<span>21<span>y3</span></span></span>+<span>9<span>y2</span></span></span>−9</span><span>y2</span></span></span></span></span><span>=<span><span><span><span><span><span><span>−<span>149<span>y4</span></span></span>−<span>84<span>y3</span></span></span>+<span>36<span>y2</span></span></span>−36</span><span><span>4y</span>y</span></span></span></span></span><span>=<span><span><span><span><span><span>−<span>149<span>y4</span></span></span>−<span>84<span>y3</span></span></span>+<span>36<span>y2</span></span></span>−36</span><span>4<span>y<span>2</span></span></span></span></span></span>