4. A rectangular back yard ice rink is to have an area of 1200m', and will be surrounded by boards.
a) What are the dimensions of the ice rink that can be enclosed for the least cost of boards? b) If one board is 2.0 m long, how many boards would you need to enclose the rink?

21

step-by-step explanation:

a

step-by-step explanation:

rurbrbrjrnrbjr

answer: solve 5\cdot 2^x=2405⋅2  

x

=2405, dot, 2, start superscript, x, end superscript, equals, 240.

solution

to solve for xxx, we must first isolate the exponential part. to do this, divide both sides by 555 as shown below. we do not multiply the 555 and the 222 as this goes against the order of operations!

\begin{aligned} 5\cdot 2^x& =240 2^x& =48 \\ \end{aligned}  

5⋅2  

x

2  

x

​    

=240

=48

​

step-by-step explanation: