Answer:
The statement is False.
Step-by-step explanation:
Consider the provided information.
If a linear system has four equations and seven variables, then it must have infinitely many solutions.
We need to determine the above statement is true or false.
The above statement is false, it could be inconsistent, and therefore have no solutions,
For example:

Hence, there is no solution.
The value of Sin(a) suppose that Cos B = 0.68 in which case, a + B = 90° is; 0.68.
<h3>Trigonometry</h3>
First, when we have two angles, whose sum equals, 90°.
In essence, Since the algebraic sum of angles A and B is 90°;
By trigonometric identity;
Where; (90 - A) = B.
Therefore; Sin A = Cos B = 0.68.
Read more on trigonometry;
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