Question

упростите выражение
2 c(1+c)-(c-2)(c+4);
(у+2)2-2у(у+2);
30х+3(х-5)2;

Answer 1

1) 2 c(1+c)-(c-2)(c+4) = 2c+2c^{2}-(c^{2}+4c-2c-8)=2c+2c^{2} -c^{2} -4c+2c+8=c^{2} +8
2) (у+2)2-2у(у+2) = 2y+4-2y^{2}-4y = -2y^{2}-2y+4
3) 30x+3(x-5)2 = 30x +(6x-15)2=30x + 12x-30=42x-30