Question

(3a-7)² = 9a² -_______+49​

Answer 1

Answer:

Using the identity

$(x - y) {}^{2} = x {}^{2} - 2xy + y {}^{2}$

here x = 3a and b = 7

$(3a - 7) {}^{2} = 9a {}^{2} - 42a + 49$

So, the value in the dash will be 42a.