We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.

+0

# Help please, thanks.

0
522
2

Find the value of $y$ such that $9^y = \dfrac{3^5\cdot 9^6}{27^3}$.

Got 7 the first time and 1 the sencond time... Don't know what's wrong...

Thanks in advance.

Jul 25, 2018
edited by Guest  Jul 25, 2018

### 2+0 Answers

#1
0

9^y = (3^5×9^6)/27^3 solve for y

9^y = 6,561             factor both sides

3^2y = 3^8             equate the exponents

2y = 8                       divide both sides by 2

y = 8/2

y = 4

Jul 25, 2018
#2
+1

Find the value of $y$ such that $9^y = \dfrac{3^5\cdot 9^6}{27^3}$. $$\begin{array}{|rcll|} \hline 9^y &=& \dfrac{3^5\cdot 9^6}{27^3} \\\\ 9^y &=& \dfrac{3^5\cdot 9^6}{(3\cdot 9)^3} \\\\ 9^y &=& \dfrac{3^5\cdot 9^6}{3^39^3} \\\\ 9^y &=& 3^{5-3}\cdot 9^{6-3} \\ 9^y &=& 3^{2}\cdot 9^{3} \\ 9^y &=& 9\cdot 9^{3} \\ 9^y &=& 9^1\cdot 9^{3} \\ 9^y &=& 9^{3+1} \\ 9^{{\color{red}y}} &=& 9^{{\color{red}4}} \\\\ \mathbf{y} & \mathbf{=} & \mathbf{4} \\ \hline \end{array}$$ Jul 25, 2018