I can see the question but if you add a picture maybe i’ll understand it a little more
2a and 15a. These are like terms due to the fact they have the same variables in this case "a".
To find c you use cosine or adjacent/hypotenuse. To set up your equation it’ll look like h=16/cos(21). h=hypotenuse which is what your solving for. You should get 17.1383199. I’m not sure what your supposed round to so I gave the full answer.
12 3/8 turn the 1/4 into 2/8 and add that to 1/8 and you get 3/8. add 5 and 7 to get 12.
<span>(x – 13)(x + 8) = 196
</span>x * x + x * 8 - 13 * x - 13 * 8 = 196
x² + 8x - 13x - 104 = 196
x² - 5x - 104 - 196 = 0
x² - 5x - 300 = 0
The missing side length is 28
