√3x² + 3x - 7 = 2x - 1
3x² + 3x - 7 = ( 2x - 1)²
3x² + 3x - 7 = ( 2x - 1)( 2x - 1)
3x² + 3x - 7 = 4x² - 4x + 1
3x² + 3x - 7 - 4x² + 4x - 1 = 0
- x² + 7x - 8 = 0
x² - 7x + 8 =0
D = b²- 4ac = (-7)² - 4 × 1 × 8 = 49 - 32 = 17
x1,2 = 7 +/-√17 / 2
( x - 3) / (7 + x) = 1/9
9( x - 3) = 7 + x
9x - 27 = 7 + x
9x - x = 27 + 7
8x = 34
x = 34/8
x = 4,25
А)=х^2-7х-3х+21-6х^2+10х=21-5х^2
б)=4а^2-8а-16+8а-а^2=3а^2-16
в)=2m^2+4m+2-4m=2m^2+2
1)a/b+b/a+2=(a²+b²+2ab)/ab=(a+b)²/ab
2)(a_b)/2a-b/(a+b)=(a²+2ab+b²-2ab)/[2a(a+b)]=(a²+b²)/[2a(a+b)]
3)(a+b)²/ab *(a²+b²)/[2a(a+b)]=(a+b)(a²+b²)/2a²b
4)a+2b +b²/a=(a²+2ab+b²)/a=(a+b)²/a
5)a/(a+b)+b/(a-b)=(a²-ab+ab+b²)/(a²-b²)=(a²+b²)/(a²-b²)
6)(a+b)²/a*(a²+b²)/[(a-b)(a+b)]=(a+b)(a²+b²)/[a(a-b)]
7)(a+b)(a²+b²)/2a²b :(a+b)(a²+b²)/[a(a-b)]=
=(a+b)(a²+b²)/2a²b *a(a-b)/[(a+b)(a²+b²)]=(a-b)/2ab
a=3/4,b=4/3
(3/4-4/3);(2*3/4*4/3)=(9-16)/12:2=-7/24
A1=-1,5-1,5=-3;
a6=-1,5-9=-10,5;
S6=(a1+a6)*6/2=(-3-10,5)*6/2=-13,5*3=-40,5;
Ответ: S6=-40,5