Выражение: (5*x+4)*(25*x^2-20*x+16)-64=125*x^3
1. (5*x+4)*(25*x^2-20*x+16)=125*x^3+64
2. 64-64=0
125*x^3=125*8=1000
Ответ: 1000
Y=4x-30
B(7,-3), x=7,y=-3
4.7-30=28-30=-2≠-3
Ne proxodit.
![\sqrt{x+7}+ \sqrt{x-2}=9](https://tex.z-dn.net/?f=+%5Csqrt%7Bx%2B7%7D%2B+%5Csqrt%7Bx-2%7D%3D9)
ОДЗ:
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{x+7≥0 {x≥-7 ---[-7]-------------------->
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{x-2≥0 {x≥2 -------------[2]----------->
x≥2
![(\sqrt{x+7}+ \sqrt{x-2})^2=9^2 \\ x+7+x-2+2 \sqrt{(x+7)(x-2)}=81 \\ 2 \sqrt{(x+7)(x-2)}=81-5-2x \\2 \sqrt{(x+7)(x-2)}=76-2x|:2 \\ \sqrt{(x+7)(x-2)}=38-x \\ \left \{ {{38-x \geq 0} \atop {(\sqrt{(x+7)(x-2)})^2=(38-x)^2}} \right. \\ \left \{ {{x \leq 38} \atop {x^2+7x-2x-14=1444+x^2-76x}} \right. \\ \left \{ {{x \leq 38} \atop {5x+76x=1444+14}} \right. \\ \left \{ {{x \leq 38} \atop {81x=1458}} \right. \\ \left \{ {{x \leq 38} \atop {x=18}} \right.](https://tex.z-dn.net/?f=%28%5Csqrt%7Bx%2B7%7D%2B+%5Csqrt%7Bx-2%7D%29%5E2%3D9%5E2+%5C%5C+x%2B7%2Bx-2%2B2+%5Csqrt%7B%28x%2B7%29%28x-2%29%7D%3D81+%5C%5C+2+%5Csqrt%7B%28x%2B7%29%28x-2%29%7D%3D81-5-2x+%5C%5C2+%5Csqrt%7B%28x%2B7%29%28x-2%29%7D%3D76-2x%7C%3A2+%5C%5C+%5Csqrt%7B%28x%2B7%29%28x-2%29%7D%3D38-x+%5C%5C+%5Cleft+%5C%7B+%7B%7B38-x+%5Cgeq+0%7D+%5Catop+%7B%28%5Csqrt%7B%28x%2B7%29%28x-2%29%7D%29%5E2%3D%2838-x%29%5E2%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+38%7D+%5Catop+%7Bx%5E2%2B7x-2x-14%3D1444%2Bx%5E2-76x%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+38%7D+%5Catop+%7B5x%2B76x%3D1444%2B14%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+38%7D+%5Catop+%7B81x%3D1458%7D%7D+%5Cright.+%5C%5C+%5Cleft+%5C%7B+%7B%7Bx+%5Cleq+38%7D+%5Catop+%7Bx%3D18%7D%7D+%5Cright.+)
Ответ: х=18
9X-3>10X-14
9X-10X>-14+3
-X>-11
X<11