Let me get you started with the first two, and then you show us how you might start the other two.
Step 1: Subtract 6x from both sides of the equation to get the variable to one side of the equation.
Step 2: Add 4 to both sides to isolate the variable (get it to one side by itself).
Step 3: Finally, divide both sides by 86 and simplify.
Step 1: Use the distributive property to simplify the equation.
Step 2: Combine like terms.
Step 3: Add 21 to each side.
Step 4: Add 3t to both sides.
Step 5: Finally, divide both sides by 6.
Good luck with the other two. Let us know if you have problems. Show us some of your work.