Give examples to illustrate the meaning of the following algebraic formula: 1) 3a-b: (2) π a ^ 2: (3) x ^ 2-y ^ 2: (3) x + y + Z / 3:

3a-b for example, a equals 5 and B equals 10, that is, 3 times 5 minus 10

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11. 3A = half B, a: B = (): ()
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