= (6,25a^2*y^4 + 10ay^3 + 4y^2) + 18,75a^2*y^4 = (2,5ay^2+2y)+18,75a^2*y^4
n^2+7n+12=n^2+3n+4n+12=n(n+3)+4(n+3)=(n+3)(n+4),
1)640-90=550
2)60×8+236=480+236=716
1) -5,52:1,4 = -552/52 : 14/10 = -552·10/14 = - 276/70
2)-276/70·7/8 =- 69/20 = -3 9/20 = -3,45
3) 6,8 - 3,45 = 3,35