3х-(9-3)=3(4-2х)
Раскрываем скобки
27х-9x=12-6x
27x-9x+6x=12
24x=12
x=0.5
Вроде так
4x²-1-4x+6=20
4x²-4x-15=0
D=16-4*4*(-15)=256=16²
x=(4+16)/8=2,5
x=(4-16)/8=-1,5
<span>а)a^3+a^2b +ax+ bx=(b+a)*(x+a^2)</span>
<span>б)<span>a^6 +a^5-a^4-a^3=(a-1)*a^3*(a+1)^2</span></span>
<span><span>в)<span>x^4y-x^3-y^2+5zy-5zx=5*y*z-5*x*z-y^2+x^4*y-x^3</span></span></span>
<span><span><span>г)<span>a^4x^4-a^3x^3+z^2-axz^2=-(a*x-1)*(z^2-a^3*x^3)</span></span></span></span>
<span><span><span><span>д)<span>ax+ay+bx+by-cx-cy=-(c-b-a)*(y+x)</span></span></span></span></span>
<span><span><span><span><span><span>е)a^2x-ax^2+3x-3a+ac-cx=-(x-a)*(a*x+c-3)</span></span></span></span></span></span>
<span><span><span><span><span><span><span>ж)x^4+x^3+abx-c^2x+ab-c^2=(x+1)*(x^3-c^2+a*b)</span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span>з)a^5-a^4x-ab+x^5-ax^4+bx=(x-a)*(x^4+b-a^4)</span></span></span></span></span></span></span></span>
Второй день телефоны - 3а
всего 1 день-а+б 2 день 3б+3а