3)
x - 7 = 14
x = 14 + 7
x = 21
4)
21 - 5x = 6
-5x = 6 - 21
-5x = -15
x=3
5)
x + x + 4 + x = 16
3x = 16 - 4
3x = 12
x = 12/3
x = 4
6)
<span>х + 5 + х + 6 = 21
</span>2x = 21 - 11
2x = 10
x = 10/2
x = 5
7)
<span>х + 2х - 5 = 40
</span>3x = 40 + 5
3x = 45
x = 45/3
x = 15
8)
0.1x = 3
x = 3/0.1
x = 3 * 10
x = 30
2+3(x+5y)=-(2x+3y)⇒2+3x+15y+2x+3y=0⇒5x+18y+2=0
3x+4y=-8⇒y=-2-0,75x
5x-36-13,5x+2=0
8,5x=-34
x=-34:8,5=-4
y=-2-0,75*(-4)=-2+3=1
∛5 я представил как Х ⇒∛25=х², отсюда
_____32_____ - ∛5 = ____32_____ - Х =___32 - 9Х +3Х² - 5___ =
9-3∛5+∛25 9-3Х+Х² 9-3Х+Х²
=___3· (9-3Х+Х²)___ = 3
9-3Х+Х²