1) х>a
х-а=2
х<a
а-х=2 х-а=2 х1=2+а
а-х=2 х2=а-2
Х=х1+х2 тут первое со вторым совокупность а все система
2+а+а-2=12
2а=12
а=6
Ответ 6
Mn=14
m+n=9
m=9-n
n(9-n)=14
9n-n²-14=0
n²-9n+14=0
D=81-56=25
n1=(9+5)/2=7
n2=(9-5)/2=2
1) n=7
m=9-7=2
2) n=2
m=9-2=7
Ответ: (7;2);(2;7)
A6=8
a7=10
a8=12
a9=14
a10=16
![\sqrt{-30 - 2x} = - 19 - x \\ \left \{ {{-30 - 2x \geq 0} \atop {-30 - 2x=(- 19 - x)^{2} }} \right. \\ \left \{ {{- 2x \geq 30} \atop {-30 - 2x= (-1)^{2}*(19 + x)^{2} }} \right. \\ \left \{ {{x \leq - 15} \atop {-30 - 2x= (19 + x)^{2} }} \right. \\ \left \{ {{x \leq - 15} \atop {-30 - 2x= 361 + 38x+ x^{2} }} \right. \\ \left \{ {{x \leq - 15} \atop {x^{2}+ 40x+391 = 0}} \right. \\](https://tex.z-dn.net/?f=%5Csqrt%7B-30+-+2x%7D+%3D+-+19+-+x+%5C%5C+%5Cleft+%5C%7B+%7B%7B-30+-+2x+%5Cgeq+0%7D+%5Catop+%7B-30+-+2x%3D%28-+19+-+x%29%5E%7B2%7D+%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7B-+2x+%5Cgeq+30%7D+%5Catop+%7B-30+-+2x%3D+%28-1%29%5E%7B2%7D%2A%2819+%2B+x%29%5E%7B2%7D+%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+-+15%7D+%5Catop+%7B-30+-+2x%3D+%2819+%2B+x%29%5E%7B2%7D+%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+-+15%7D+%5Catop+%7B-30+-+2x%3D+361+%2B+38x%2B+x%5E%7B2%7D+%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+-+15%7D+%5Catop+%7Bx%5E%7B2%7D%2B+40x%2B391+%3D+0%7D%7D+%5Cright.+%5C%5C)
![D=1600 - 4*391 = 1600 - 1564 = 36 \\ \sqrt{D} = 6 \\ x1 = - 17 ; x2 = - 23](https://tex.z-dn.net/?f=+D%3D1600+-+4%2A391+%3D+1600+-+1564+%3D+36+%5C%5C+%5Csqrt%7BD%7D+%3D+6+%5C%5C+x1+%3D+-+17+%3B+x2+%3D+-+23)
Оба корня удовлетворяют условию Х ≤ 15
Ответ: -17; -23