<span>7-2(x-4.5)=6-4x
7-2x+9=6-4x
-2x+4x=6-7-9
2x=-10
x=-5
</span>
С=(b₁-a₁;b₂-a₂)=(-1-a₁;2-a₂)=(2;3)
a₁=-1-2=-3
a₂=2-3=-1
(7,42*5/9-(-11,48):1 4/5):0,35
1)7.42*5=37.1
2)37.1/9=371/90
3)11.48/14=0.82
4)0.82/5=41/250
5)-(-41/250)=41/250
6)371/90+41/250=4822/1125
7)4822/0.35=96440/7
8)96440/1125=19288/225
9)1/(7*225)=1/1575
Ответ: 19288/1575=12+(388/1575)
(a+2)*(a-2)=a^2-4
<span>(3b-1)*(3b+1)=</span>9b^2-1
Решение
cos²(a/2) = (1 + cosa)/2
(1 + cosa)/2 = (1 + 0,6)/2 = 1,6 / 2 = 0,8