∠1 and angle, 2∠2 are vertical angles. If mangle, 1, equals, left bracket, 3, x, plus, 21, right bracket, degrees∠1=(3x 21) ∘ and mangle, 2, equals, left bracket, 4, x, minus, 2, right bracket, degrees∠2=(4x−2) ∘ , then find the value of x.