62x4+44x5+5x18=62x4+（44+18=62）x5=62x（5+4）=558
62×4+44×5+5×18=62×4+（44+18）×5=62×4+62×5=62×（4+5）=62×9=62×10-62×1=620-62=558
62×4+44×5+5×18＝248+220+90＝558
