Answer:
x = 20
Step-by-step explanation:
we are given the value of f(x), replace it in the first equation
15 = x - 5
solve for x by adding 5 on both sides
15 + 5 = x
20 = x or x = 20
Answer:
3
Step-by-step explanation:
Because 30 divided by 5 =6 which is the miles so divide 15 by 5 and the minutes are 6 so 6x5 so 3
Answer:
Identity is verified.
Step-by-step explanation:
We have to verify the identity 
To prove any identity we always prove one side(either left hand side or right hand side) of the equation equal to the other side.
In this identity we take the left hand side first

(as we know cos(a+b) = cosa×cosb-sina×sinb)


= - sinx ( Right hand side)
Hence identity is proved.
let apple juice = x
milk = 2x
fruit punch = 3x
3x + 2x + x = 660
6x = 660
x = 660/6
x = 110 apple juices
2*110 = 220 milks
3*110 = 330 fruit punches