1.
1) (с-6)² = с²-12с+36
2) (2а-3b)² = 4a²-12ab+9b²
3) (5-a)(5+a) = 25-a²
4) (7x+10y)(10y-7x) = 100y²-49x²
2.
1)b²-49 = (b-7)(b+7)
2)c²-8c+16 = (c-4)²
3)100-9x² = (10-3x)(10+3x)
4)4a²+20ab+25b² = (2a+5b)²
3.
(x-2)(x+2)-(x-5)² = x²-4-x²+10x-25 =10x-29
4.
4(3y+1)²-27=(4y+9)(4y-9)+2(5y+2)(2y-7)
36y²+24y+4-27=16y²-81+20y²-70y+8y-28
86y=-86
y=-1
1.
1) (с-6)² = с²-12с+36
2) (2а-3b)² = 4a²-12ab+9b²
3) (5-a)(5+a) = 25-a²
4) (7x+10y)(10y-7x) = 100y²-49x²
2.
1)b²-49 = (b-7)(b+7)
2)c²-8c+16 = (c-4)²
3)100-9x² = (10-3x)(10+3x)
4)4a²+20ab+25b² = (2a+5b)²
3.
(x-2)(x+2)-(x-5)² = x²-4-x²+10x-25 =10x-29
4.
4(3y+1)²-27=(4y+9)(4y-9)+2(5y+2)(2y-7)
36y²+24y+4-27=16y²-81+20y²-70y+8y-28
86y=-86
y=-1