Answer:
C. f(-1) =12
Step-by-step explanation:
f(x)= 3x^2+9
Let x=-1
f(-1) = 3(-1)^2 +9
= 3(1)+9
= 3+9
= 12
f(-1) =12
Answer:
17
Step-by-step explanation:
2x+10, multiply to two each term x and 5
Answer:
k = 5
General Formulas and Concepts:
<u>Pre-Algebra</u>
- Order of Operations: BPEMDAS
- Equality Properties
Step-by-step explanation:
<u>Step 1: Define equation</u>
15 - 3k = 10(k - 5)
<u>Step 2: Solve for </u><em><u>k</u></em>
- Distribute 10: 15 - 3k = 10k - 50
- Add 3k to both sides: 15 = 13k - 50
- Add 50 to both sides: 65 = 13k
- Divide 13 on both sides: 5 = k
- Rewrite: k = 5
<u>Step 3: Check</u>
<em>Plug in k into the original equation to verify it's a solution.</em>
- Substitute in <em>k</em>: 15 - 3(5) = 10(5 - 5)
- Subtract: 15 - 3(5) = 10(0)
- Multiply: 15 - 15 = 0
- Subtract: 0 = 0
Here we see that 0 does indeed equal 0.
∴ k = 5 is a solution of the equation.