Question

write a two - column proof. given: m∠gfi = 141°. prove: m∠efi = 48°. 2. m∠gfe + m∠efi = m∠gfi 2. angle addition postulate. 3. m∠gfe + m∠efi = 141°. 3. substitution property, (steps 1, 2). 4. m∠gfe=(8x - 3)°, m∠efi = 4x°. 4. given. 5. 8x - 3+4x = 141. 5. substitution property. 6. 12x - 3 = 141. 6. combine like terms. 7. 12x = . 7. addition property of equality.

Explanation:

Step1: Recall addition property of equality

We have the equation \(12x - 3=141\). To isolate the term with \(x\), we add 3 to both sides of the equation.

Step2: Perform the addition

\[

$$\begin{align*} 12x- 3+3&=141 + 3\\ 12x&=144 \end{align*}$$

\]

Answer:

144