Basic trig concepts you have to keep in mind:
SOH CAH TOA
Sine: Opposite of the angle over the hypotenuse
Cosine: Adjacent over hypotenuse
Tangent: Opposite over adjacent
I'll do one of the problems, you should be able to do the rest (It's good practice ;))
Look at the picture.
a)
180° - 45° = 135°b) Use trigonometric function
270° - 56° = 214°
Answer:$8.50
Step-by-step explanation: If 4 apples are $1.00 that means that one apple would be 25¢. 10 apples would mean $8.00 and since 2 apples are left that would be 50¢. Hence, the answer would be $8.50
28x+20y =14*4 = 56
28x + 21y = 9*7 =56
=> y=0, x = 2