Question

278,74-(6,5b-b)=276,84

Answer 1

$278.74 - (6.5b - b) = 276.84 \\ - 5.5b = 276.84 - 278.74 \\ - 5.5b = - 1.9 \\ b = \frac{19}{55} = 0.34 \\ b = 0.34$