
To solve x:
1. Substract 19 in both sides of the equation:

2. Multiply both sides of the ewuation by 10/9:

<h2>Then, the value of x is 60 (x=60)</h2>
We let x be the length (in minutes) of a certain science class. 65% of this period is spent with the experiment which lasted for about 52 minutes. Mathematically, this can be expressed as,
52 = (0.65)(x)
The value of x from the generated equation is 80. Thus, the science class is 80 minutes long.