Answer:
C. f(5) = 13 and f(-3) = -3
General Formulas and Concepts:
<u>Pre-Algebra</u>
- Order of Operations: BPEMDAS
Step-by-step explanation:
<u>Step 1: Define</u>
f(x) = 2x + 3
x = 5
x = -3
<u>Step 2: Evaluate</u>
x = 5
- Substitute: f(5) = 2(5) + 3
- Multiply: f(5) = 10 + 3
- Add: f(5) = 13
x = -3
- Substitute: f(-3) = 2(-3) + 3
- Multiply: f(-3) = -6 + 3
- Add: f(-3) = -3
Cosα=x/L
L=x/cosα, we are told that the ladder base is 48 ft from the base of the wall and α=39° so:
L=48/cos39 ft
L≈61.76 ft (to nearest hundredth of a foot)
Answer:
x =-1
Step-by-step explanation:

replace y by 2x +4 in the first equation
2(2x + 4) = 6x + 10
4x + 8 = 6x + 10
-2x +8 = 10
-2x = 2
x = -1