9p^2-6p5q^2 in standard form it would be: 9p^2+5q^2-6p
The third is because the prove is x = fifteen and if a number is next to a letter, it means multiply, sorry I could only do one.
17. The answer should be 17
<u>Answer:</u>
Angle A = 39°
<u>Step-by-step explanation:</u>
We are given that there is a triangle ABC where a = 9, c = 5 and angle B = 120° and we are to find the measure of angle A.
But first we need to find the side b using the law of cosine:



Now finding angle A using law of cosine:




Therefore, the measure of angle A = 39°.