67.8k views
13 votes
Pls Help, Max Points

Pls Help, Max Points-example-1

2 Answers

8 votes


\\ \rm\Rrightarrow log_7(5-x)-log_7(3+x)=-1

  • Side change


\\ \rm\Rrightarrow log_7(5-x)=-1+log_7(3+x)

  • log_a^b+log_a^c=log_^(bc)


\\ \rm\Rrightarrow 7(5-x)=3+x


\\ \rm\Rrightarrow 35-7x=3+x


\\ \rm\Rrightarrow 35-3=x+7x


\\ \rm\Rrightarrow 32=8x


\\ \rm\Rrightarrow x=4

User Bob Barcklay
by
8.5k points
2 votes

Answer:

x = 4

Explanation:


\large \boxed{\begin{minipage}{7.5 cm}\underline{Log Laws} \\ \\$\textsf{Quotient law}: \quad \log_ax - \log_ay=\log_a(x)/(y) \\ \\\textsf{If }\: \log_ab=c\: \textsf{ then }\: a^c=b$\\\end{minipage}}


\large \begin{aligned}\log_7(5-x)-\log_7(3+x) & =-1\\\\\log_7\left((5-x)/(3+x)\right) & =-1\\\\\left((5-x)/(3+x)\right) & =7^(-1)\\\\(5-x)/(3+x) & =(1)/(7)\\\\7(5-x) & =3+x\\\\35-7x & =3+x\\\\35-3 & =x+7x\\\\8x & =32\\\\x & =(32)/(8)\\\\x & =4\end{aligned}

User Cyril Cherian
by
6.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories