How to get answer by Mimiwhatsup:
Let's solve for b.
1/t = 1/a + 1/b
Step 1: Multiply both sides by t.
1= at+bt/ab
Step 2: Multiply both sides by ab.
ab=at+bt
Step 3: Add -bt to both sides.
ab+−bt=at+bt+−bt
ab−bt=at
Step 4: Factor out variable b.
b(a−t)=at
Step 5: Divide both sides by a-t.
b(a−t)/a−t = at/a−t
b= at/a−t
