(2x+3)/(x²+x-12)-1/2≤0
(4x+6-x²-x+12)/(x²+x-12)≤0
(-x²+3x+18)/(x²+x-12)≤0
(x²-3x-18)/(x²+x-12)≤0
(x-6)(x+3)/(x+4)(x-3)≤0
x=6 x=-3 x=-4 x=3
+ _ + _ +
------(-4)--------[-3]---------(3)--------[6]-------
x∈(-4;-3] U (3;6]
3задача 1700/100*115=1955
4 задача a*b-a*c+5*(b-c)
F(x)=3x²-7x+1 xo=-1
Уравнение касательной
у=f'(xo)(x-xo)+f(xo)
f'(x)=6x-7
f'(xo)=f'(-1)=6*(-1)-7=-6-7=-13
f(xo)=f(-1)=3*(-1)²-7*(-1)+1=3+7+1=11
y=-13(x-(-1))+11
y=-13x-14+11
y=-13x-3