(7-а)²

To expand the expression \((7 - a)^2\), you can use the formula for the square of a binomial, which is \((x - y)^2 = x^2 - 2xy + y^2\). Here, \(x = 7\) and \(y = a\). Applying the formula: \[ (7 - a)^2 = 7^2 - 2 \cdot 7 \cdot a + a^2 \] Calculate each term: - \(7^2 = 49\) - \(-2 \cdot 7 \cdot a = -14a\) - \(a^2 = a^2\) Putting it all together: \[ (7 - a)^2 = 49 - 14a + a^2 \] So, the expanded form of \((7 - a)^2\) is: \[ a^2 - 14a + 49 \]