Find the following product:

To find the product, we will use distributive law as follows:

$-5 a(7 a-2 b)$

$=(-5 a) \times 7 a+(-5 a) \times(-2 b)$

$=(-5 \times 7) \times(a \times a)+(-5 \times(-2)) \times(a \times b)$

$=(-35) \times\left(a^{1+1}\right)+(10) \times(a \times b)$

$=-35 a^{2}+10 a b$

Thus, the answer is $-35 a^{2}+10 a b$.