解:6.3x8.7+8.7x3.7等于( 87 ) ∵已知需求出6.3x8.7+8.7x3.7等于多少 X × Y + X × Z = X × (Y + Z) ∴6.3 x 8.7 + 8.7 x 3.7 = 8.7 × (6.3 + 3.7) = (8×10+7)/10 × 10 = 87/10 × 10 = 87 答:6.3x8.7+8.7x3.7等于87