7b/12=4.2
7b=50.4
b=7.2
hope this helps
your answer is a ok i hope this helpful
<u>Answer:</u>
<u>Step-by-step explanation:</u>
We can use the following rule of surds to solve the problem:
,
which means that when multiplying two numbers with the same bases, we can simply add their powers while keeping the base the same.
Applying this rule:

⇒ 
⇒