I’ll explain part A and you can apply it to the other parts. The functions f(x), g(x), and m(x) are all equivalent to the given polynomials. So when it asks for f(x) + [g(x) - m(x)] you plug them in. The answer to Part A is 3x^2 +5x - z + [5x^2-3x+z - 2x^2 - 2x]. Combine the like terms (3x^2+5x^2-2x^2 = 6x^2 (because 3+5-2=6)) and so on until you’ve simplified it as much as possible!
The LCD of the denominator is 12. For this one it is possible to just 'see' that 6 is a divisor of 12. When in doubt, you can always get an answer by just multiplying the denominators. (ie., you can turn 11/12 into 66/72 and 1/6 into 12/72).
In this case, the easiest is to convert 1/6 into 2/12. (multiply both numbers by 2).
Then it becomes:
The answer is 8 because four plus eight equals twelve
The legs of a triangle with a hypotenuse that measures 15 units long have lengths that are equal to 15 times the sine or cosine of the given angle.
leg 1 = (15 units) x (cos 19) = 14.18 units
leg 2 = (15 units) x (sin 19) = 4.88 units
The lengths of the legs are 14.18 units and 4.88 units.