Answer:
A=50
Step-by-step explanation:
assuming you mean 100-A+20-70=0
you need to solve for A, which means add all your numbers together and isolate A.
-A+50=0
The answer is 50 - a.
1) Collect like terms.
[tex] - a + (100 + 20 - 70)[/tex]
2) Simplify.
[tex]50 - a[/tex]
Therefor, the answer is 50 - a.
