1) 7Х+42 =20Х+16
7Х-20Х = -42 +16
- 13Х = -26
13Х = 26
<u>Х= 2</u><u />
2)1,5Х + 12 = -4Х +1
1,5Х + 4Х = -12 +1
5,5 Х = - 11
<u> </u><u> Х = - 2</u>
3) 0,75Х + 6 = 2Х +1 (т.к. 3/4 = 0,75)
0,75Х - 2Х = -6 +1
- 1,25Х = -5
1,25Х = 5
<u>Х = 4</u>
<span>7(х+6)=4(5х+4),
</span>7x + 42 = 20x + 16,
26 = 13x,
x = 2.
<span>Ответ: 2.
</span><span>1,5(х+8)=-4х+1,
</span>1.5x + 12 = 1 - 4x,
5.5x = -11,
<span>x = -2.
Ответ: -2.
</span><span>3\4(х+8)=2х+1,
</span>0.75x + 6 = 2x + 1,
-1.25x = -5,
x = 4.
Ответ: 4.