The required expression for p in terms of a is p = (a+4)/2.
9p = 3a + 1 ---(1)
7p = 2a - 3 ---(2)
Equation, is values of two expression that are equal.
Subtracting from (1) -(2).
9p-7p = 3a - 2a + 1 + 3
2p = a + 4
p = ( a + 4 )/2
Thus, the required expression for p in terms of a is p = (a+4)/2.
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