(6x-5)/5-(3x+4)/4=1/4
20*(6x-5)/5-20*(3x+4)/4=20*1/4
4(6x-5)-5(3x+4)=5
24x-10-15x-20=5
9x-40=5
9x=45
x=45/9=5
Ответ: 5
1)3x2-17x+10=0
Д=-17в квадрате - 4*3*10=169
x=17плюс минус 13 и все это делить на 6
x1=5
x2=4/6=2/3
1) 2а-3b-(4a+7b+c+3) = 2a - 3b - 4a - 7b - c - 3 = -2a - 10b - c - 3<span>2) 2xy-y^2+(y^2-xy)-(x^2+xy) = 2xy - y^2 + y^2 - xy - x^2 - xy = -x^2
</span><span>3) (-2x^2+x+1)-(x^2-x+7)-(4x^2+2x+8) = -2x^2 + x + 1 - x^2 + x - 7 - 4x^2 - 2x - 8 = -7x^2 -14 = -7(x^2 + 2)
</span><span>4) (3a^2-a+2)+(3a^2+3a-1)-(a^2-1) = 3a^2 - a + 2 + 3a^2 + 3a - 1 - a^2 + 1 = 5a^2 + 2a + 2
</span><span>5) (1-x+4x^2-8x^3)+(2x^3+x^2-+x-3)-(5x^3-8x^2) = 1 - x + 4x^2 - 8x^3 + 2x^3 + x^2 + x - 3 - 5x^3 + 8x^2 = -11x^3 + 14x^2 - 2
</span><span>6) (0.5a-0.6b+5.5)-(-0.5a+0.4b)+(1.3b-4.5) = 0.5a - 0.6b + 5.5 + 0.5a - 0.4b + 1.3b - 4.5 = a + 0.3b + 1
</span><span>7) (x^2)^4*(x^4)^3 = x^8 * x^12 = x^(8 + 12) = x^20
</span><span>8) (a^2*a^3)^4 = a^4(2 + 3) = a^(4*5) = a^20</span>
8×0.018=0.144
0.144÷1.2=0.12