recall that the sum of all interior angles in a triangle is 180°, therefore
[tex]\bf \stackrel{A}{(48)}~+~\stackrel{B}{(6x-28)}~+~\stackrel{C}{2x}~=~180\implies 8x+20=180
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8x=160\implies x=\cfrac{160}{8}\implies x=20\\\\
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\measuredangle B=6(20)-28\qquad \qquad \qquad \measuredangle C=2(20)[/tex]