45b+6a-3ab-90= x во 2ой -у во 2ой-х-у= 60+6ab-3ab-12a= - вопрос №5484264456390226063125532 от lagodaviktoria2 02.01.2021 17:21

Question

Алгебра: 45b+6a-3ab-90= x во 2ой -у во 2ой-х-у= 60+6ab-3ab-12a= x(y-5)-y(5-y)= (3a во 2ой-a+2)+(-3a во 2ой+3а- во 2ой-1)

lagodaviktoria2 · Answer

( 45b - 3ab) + ( 6a - 90) = 3b(15 - a) + 6( a - 15) = - 3b(a -15) + 6(a - 15)=
= ( a - 15)( 6 - 3b) = 3( 2 - b)(a - 15)
x^2 - y^2 - x - y = ( x^2 - y^2) - ( x + y) = ( x - y)(x + y) - ( x + y) =
= ( x + y)(x - y - 1)
60 + 6ab - 3ab - 12a = 60 + 3ab - 12a = 3( 20 + ab - 4a)
x( y - 5) + y( y - 5) = ( y - 5)(x + y)
( 3a^2 - a + 2) + ( - 3a^2 + 3a - 1) - ( a^2 - 1) = 3a^2-a+2-3a^2+3a-1-a^2+1=
= - a^2 + 2a + 2