1) 3х + 2 = 14х - 75
3х - 14х = - 75 - 2
- 11х = - 77
х = 7
2) 2х - 1 = 3х + 99
2х - 3х = 99 + 1
- х = 100
х = - 100
3) - х + 11 - 4х = -х + 10х + 11
- 5х + 11 = 9х + 11
- 5х - 9х = 11 - 11
- 14х = 0
х = 0
4) 3х - 12 - х = - х + 2х - 12
2х - 12 = х - 12
2х - х = - 12 + 12
х = 0
5) 5х - 0,23х + 17 = - 17 - 0,23х
5х - 0,23х + 0,23х = - 17 - 17
5х = - 34
х = - 6,8
6) 0,77х - 2х + 13 = - 13 + 0,77х
0,77х - 2х - 0,77х = - 13 - 13
- 2х = - 26
х = 13
A8=a1+7d
a1=a8-7d=-26-7*(-2)=-26+14=-12
S12=<u>2a1+d(12-1)</u> *12=( 2*(-12)-2*11)*6= (-24-22)*6=-46*6=-276.<u>
</u> 2<u>
</u>
<span>(а-2)^2-a(3a-4) = a^2 - 4a + 4 - 3a^2+4a = 4 - 2a^2 = 2(2 - a^2) = 2(2 - (-3/2)) = 2(2+3/2))= 2*3,5 = 7</span>
46√6*√3/2 *(-√2)/2=-46√6*√6/4=-46*6/4=-69