Answer:
<h3>900000</h3>
Step-by-step explanation:
<h3>5 x 4 x 5 x 5 x 5 x 3 x 4 x 3 = 900000</h3>
<em>*To solve for a specified variable, you need to isolate that variable onto one side.</em>
<h3>11.</h3>
Firstly, subtract 5r on both sides: 
Lastly, divide both sides by 2 and <u>your answer will be
</u>
<h3>12.</h3>
First, subtract z on both sides of the equation: 
Next, divide both sides by y and <u>your answer will be
</u>
<h3>13.</h3>
Firstly, multiply both sides by b: 
Next, divide both sides by c and <u>your answer will be
</u>
I think this is the answer, sorry I am not 100% sure