1-1
2-3 7х^2-5x+3-(5x^2-4)=2x^2-5x+7
3-4
4-1
5_ А(3) Б(4) В(1)
6. 30+15х-5=35х-25
15х-35х=-25-30+5
-20х=-50
х=50/20 или 5/2 или 2.5
7. 2-35*(-1/4)*(1/7)=2-5*(-1/4)=2+5/4=2+1.25=3.25
1.(2x+1)^3-27=(2x+1)(4x^2+1-27*2x+1+27^2)
2.ab^4-4ax^2=(a^2b^2)^2-(4ax)2=(a^2b^2-4ax)(a^2b^2+4ax)
X²+2·5/2·x+(5/2)²=x²+5x+25/4=(x+5/2)²;
x²-2·7·x+7²=x²-14x+49=(x-7)²
[{sinx <0 ; - sinx =sinx+2cosx .{sinx ≥ 0 ; sinx = sinx +cosx.
[ {sinx <0 ;tq x = -2 .{sinx ≥ 0 ; cosx = 0 .
[x = - arctq2 +2π*k ,k∈Z ; x =π/2 +2π*k ,k∈Z.