Concept:Simplify the given linear equation to find the value of x, then substitute it into the required expression.Explanation:First, simplify the inner bracket: 2x−21−x​=24x−(1−x)​=25x−1​.Substitute back: 47x−1​−71​⋅25x−1​=4.This gives 47x−1​−145x−1​=4.Find a common denominator (28): 2849x−7​−2810x−2​=4.Combine: 2849x−7−(10x−2)​=2839x−5​=4.Multiply both sides by 28: 39x−5=112.So 39x=117, hence x=3.Now evaluate 3x−15x−3​=3(3)−15(3)−3​=9−115−3​=812​=23​.Answer:D. 23​