Formula for perimeter of a rectangle: P = 2W + 2L
Here, P = 2(x-3 ) cm + 2(3x+7) cm = 2x - 6 + 6x + 14 (cm)
Combine like terms: 8x + 8 cm (simplest form) This is the perimeter.
Now let x = 4: P(x=4) = 8(4) + 8 cm = 40 cm
Answer: D
Explanation: For this problem you can substitute f(x) and x for 21 and -6 respectively.
Thus, we have 21=-3(-6)+4
Answer: 9 so the fraction would be 9/24
Cosα=x/L
x=Lcosα, we are told the ladder is 10ft and α=42.5 so
x=10cos42.5° ft
x≈7.37 ft (to nearest hundredth of a foot)
Simply plug in the value for x.
If x is equal to -18, then plug in -18 for x.
Example:
f(x) = 15 + x/5.
f(5) = 15 + 5/5.
Then solve the equation.
A function is just something that receives some value and then barfs a value out. This is an IO relationship. (Input/Output).
