PLEASE HELP WILL GIVE BRAINLIEST

Answer:
x = 14
Step-by-step explanation:
Solve for x by simplifying both sides of the equation, then isolating the variable.
1. Multiply both sides of the equation by -8 to eliminate the fraction.
-8(3x/-8) = -8(-21/4)
2. Simplify both sides.
3x = -21x-8/4
3. Calculate the right side.
3x = 168/4
3x = 42
4. Divide both sides by 3.
3x/3 = 42/3
5. Simplify.
x = 14