1.а)6cd ∙ 2ac=2с(3d∙a)
б)<span>4m ∙ (–5n) ∙ (–8k)=160mnk
2.</span><span>4 – 12b – 2a + 5b – a=4-7b-3a
3.x+3x+x-150
4.</span><span>11n – (7n – 1) – 6n + 8 при n = 16
11 </span>∙ 16 - (7∙16-1)-6∙16+8=176-111-88=23
5. <span>4 (2а – c) – 5(а + 3c)= 8a-4c-5a-15c = 3a-19c
6.</span>у – х – 1= <span>ab – 1-ab-1-1= -3
7.</span><span>х (у + z) – y (x + z) – z (x – y)=xy+xz-yx-yz-zx+zy=0
8.Извини , не знаю Если пойму , отпишусь.</span>
По формуле (a-b)(a+b)=a²-b²
=(√15²)-(2√5)²=15-(4*5)=15-20=-5
3√32=√9*32=√288
16*16=√256
17*17=√289
Между 16 и 17
(x-7)^2=2x^2+11x+23
x^2+14x-49=2x^2+11x+23
x^2+14x-2x^2-11x=49+23
3x=72
x=72/3
x=24
Ответ:24