2x - y = -1 4х - 2у = -2
-4x + 3y = -3 <span><u>-4x + 3y = -3</u></span><span>
у = -5
х = (2у - 2) / 4 = -12 / 4 = -3 </span>
<span><span>1) </span>область определения D(</span><span>g) = ( - оо ; + оо )</span>
2) <span>f(x) = 5x-1</span> где D(f)= [-2;2]
Нули функции :
<span>f(x) = 0
</span><span>5x-1 = 0
</span>5x = 1
<u>х = 1/5</u>
Промежутки знакопостоянства:
<span>f(x) > 0 при х ∈ ( 1/5 ; 2)
</span> <span>f(x) < 0 при х ∈ ( -2 ; 1/5)</span>
Область значений функции :
f(-2) = <span>5*(-2) -1</span> = -11
f(2) = 5*2 -1 = 9
E(f)= [-11;9]
3) а= 0,00073 * 10^15 = 7,3 * 10^11 <span>порядок числа: 11
</span><span>а) а * 10^7 = </span>7,3 * 10^11 * 10^7 = <span>7,3 * 10^18
б) а * 0,001 </span><span>= 7,3 * 10^11 * </span><span><span>10^-4 </span></span><span><span>= 7,3 * 10^7
в) а^2 * 0,000001</span> </span><span>= (7,3 * 10^11 )</span>^2 * 10<span>^-7 </span><span>=
</span><span>= 7,3 </span>^2 * ( 10^11 )^2 * 10^-7 <span>= </span>53.29* 10^11* 10^-7 =
= 53.29* 10^4
4) а)<span> = </span><span>a/b + </span>b/a = <span>(a² + </span>b²)/a<span>b
</span><span><span> б) = 1/а* (1/а + 1/b) = </span></span><span>1/а* (a+b)</span>/ab = (a+b)/a²<span>b</span>
8/x=x/2
x^2=16
x=4 x=-4
y=8/4=2 y=4/2=2
y=8/(-4)=-2 y=-4/2=-2
(4;2) (-4;-2)