Question

Ab + c = d solve for a

Answer 1

Let's solve for a

ab+c=d

Add -c to both sides

ab+c+-c=d+-c

ab=-c+d

Divide both sides by b

ab/b=-c+d/b

a= -c+d/b

I hope that's help ! Good night .

Answer 2

Rearrange the equation to isolate A
A*b+c = d
      -c     -c
A*b=d-c
 /b    /b

Therefore the answer is A = $\frac{d-c}{b}$