Answer:
(√6 - √2)/4
Step-by-step explanation:
cos30°cos45° - sin30°sin45°
= cos (30 + 45)°
= cos 75°
= (√6 - √2)/4
The answer is 28 for this equation
Answer C : 3x^2+7xy-2y^2
equivalent to the following expression


Combine like terms

2x^2 + x^2 is 3x^2
4xy+3xy is 7xy
-y^2-y^2 is -2y^2
So expression becomes

Answer C is correct