5x-7(x-3)=4x+5
5х-7х+21= 4х+5
5х-7х-4х = -21+5
-6х = -16
х = 16/6
х = 2 4/6
3(x-2)=5x+3
3х -6 = 5х+3
3х -5х = 3+6
-2х = 9
х = -9/2
х = - 4 1/2
(27^3 / 125^6)^2/9 = (3^9 / 25^9)^2/9 = ((3/25 )^9)^2/9 = (3/25)^2 = 0.12^2 =
= 0.0144
Система:
x - y = 7 +
x + y = -3
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2x = 4
x = 2
2 - y = 7
-y = 5
y = -5
(2;-5) точка пересечения графиков
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Подставляем:
a*2 - 3*(-5) = 4
2a + 15 = 4
2a = -11
a = -5,5
1.8 a) y=
x-1 ≥ 0
x≥1
(3,8+7,15)*0,11= 10.95 * 0.11 = 1.2045
13,2:1,2-4,7= 11 - 4.7 = 6.3