a) x+9=18 b) x-1=-8 3y-8=13 12x-10=5x+11

a) To solve the equation , we need to isolate the variable on one side of the equation. Step 1: Subtract 9 from both sides of the equation. Step 2: Simplify the equation. Therefore, the solution to the equation is .b) To solve the equation , we need to isolate the variable on one side of the equation.Step 1: Add 1 to both sides of the equation. Step 2: Simplify the equation. Therefore, the solution to the equation is .c) To solve the equation , we need to isolate the variable on one side of the equation.Step 1: Add 8 to both sides of the equation. Step 2: Simplify the equation. Step 3: Divide both sides of the equation by 3. Step 4: Simplify the equation. Therefore, the solution to the equation is .d) To solve the equation , we need to isolate the variable on one side of the equation.Step 1: Subtract 5x from both sides of the equation. Step 2: Simplify the equation. Step 3: Add 10 to both sides of the equation. Step 4: Simplify the equation. Step 5: Divide both sides of the equation by 7. Step 6: Simplify the equation. Therefore, the solution to the equation is .