solve for a

a x 25 = ( 7 x 20 ) + ( 7 x 5 )a

multiply it out.
25a=140+35a
subtract 35a from both sides
-10a=140

divide both sides by -10

To solve for a, we need to isolate it on one side of the equation. Let's start by multiplying out the equation:

a x 25 = (7 x 20) + (7 x 5) a
25a = 140 + 35a

Next, we want to move the terms containing a to one side of the equation. In this case, since we want to solve for a, let's move the 35a term to the left side by subtracting 35a from both sides:

25a - 35a = 140

Simplifying this gives us:

-10a = 140

To isolate a, we need to divide both sides of the equation by -10:

-10a / -10 = 140 / -10

Which simplifies to:

a = -14

Therefore, the solution to the equation is a = -14.