She used 54 inches. 3/4 is equal to .75 so you can find 3/4 of the board by taking the fool length and multiplying it by .75 so 6•.75=4.5. So 3/4 of the board is 4.5 ft. However, the answer has to be in inches so since there are 12 inches in a foot you multiply 4.5•12 and that gives you your answer:54 inches.
Answer:

General Formulas and Concepts:
<u>Calculus</u>
Differentiation
- Derivatives
- Derivative Notation
Derivative Property [Multiplied Constant]:

Derivative Property [Addition/Subtraction]:

Derivative Rule [Basic Power Rule]:
- f(x) = cxⁿ
- f’(x) = c·nxⁿ⁻¹
Integration
Integration Rule [Reverse Power Rule]:

Integration Property [Multiplied Constant]:

Integration Methods: U-Substitution and U-Solve
Step-by-step explanation:
<u>Step 1: Define</u>
<em>Identify given.</em>
<em />
<u>Step 2: Integrate Pt. 1</u>
<em>Identify variables for u-substitution/u-solve</em>.
- Set <em>u</em>:

- [<em>u</em>] Differentiate [Derivative Rules and Properties]:

- [<em>du</em>] Rewrite [U-Solve]:

<u>Step 3: Integrate Pt. 2</u>
- [Integral] Apply U-Solve:

- [Integrand] Simplify:

- [Integral] Rewrite [Integration Property - Multiplied Constant]:

- [Integral] Apply Integration Rule [Reverse Power Rule]:

- [<em>u</em>] Back-substitute:

∴ we have used u-solve (u-substitution) to <em>find</em> the indefinite integral.
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Topic: AP Calculus AB/BC (Calculus I/I + II)
Unit: Integration
Ninety thousand five hundred twenty three
Step-by-step explanation:
so, yes, the area of a triangle is
baseline × height / 2
so, we have here
16 = 8 × height / 2 = 4 × height
height = 16/4 = 4 in.
Answer: 3
Step-by-step explanation: Hope I helped