<span>1) (2х-3)(5х+1)-(х-6)(x+6)+13х=0</span>
<span>10x^2 + 2x- 15x- 3- x^2 + 36 + 13x =0</span>
<span>9x^2 +33 =0</span>
<span>9x^2=-33</span>
<span>3x^2=-11</span>
<span>2) <span>(2х-7)2-7(7-4х)=0</span></span>
8x-14-49+28x=0
<span>32x=63</span>
<span> <span>x=63/32</span></span>
<span><span>x=одна целая 31/32</span></span>
<span><span>3)<span>(х-5)2+5(2х-1)=0</span></span></span>
<span><span><span>2x-10+10x-5=0</span></span></span>
12x=15
4x=5
x=5/4
x=одна целая 1/4
(x²-4x)²-(x²-4x+4)-16≤0
(x²-4x)²-(x²-4x)-20≤0
x²-4a=a
a²-a-20≤0
a1+a2=1 U a1*a2=-20
a1=-4 u a2=5
-4≤a≤5
{x²-4x≥-4 (1)
{x²-4x≤5 (2)
(1) x²-4x+4≥0
(x-2)²≥0⇒x-любое
(2) x²-4x-5≤0
x1+x2=4 u x1*x2=-5⇒x1=-1 U x2=5
x∈[-1;5]
150:60•10=250 д - всего в саду
Ответ : 250 деревьев.
Y'(x)=-3x^2-4x-3, y'(-2)=-7, y(-2)=10.
y-10=-7(x+2)=>y=-7x-4.
Ответ: y=-7x-4