Angles A and B are located in the first quadrant such that sinA=7/25 and cosB=5/13. Determine the exact value for cos (a-b).
I know this includes having to use compound angle formulas but in don't know where to go with this.

(05.08a)triangle abc is transformed to similar triangle a′b′c′ below: a coordinate plane is shown. triangle abc has vertices a at 2 comma 6, b at 2 comma 4, and c at 4 comma 4. triangle a prime b prime c prime has vertices a prime at 1 comma 3, b prime at 1 comma 2, and c prime at 2 comma 2. what is the scale factor of dilation? 1 over 2 1 over 3 1 over 4 1 over 5

Askyscraper is 396 meters tall. at a certain time of day, it casts a shadow that is 332 meters long.at what angle is the sun above the horizon at that time?

Abcd is a square. what is the measure of angle bac