A simple method is used to calculate: 7.74 × (2.8-1.3) + 1.5 × 2.26

A simple method is used to calculate: 7.74 × (2.8-1.3) + 1.5 × 2.26

7.74×(2.8-1.3)+1.5×2.26=7.74×1.5+1.5×2.26=(7.74+2.26)×1.5=10×1.5=15.