Resolver {l}{{(T)}=-9*10^{-8}*T^3+9*10^-6*T^2}{a=-7*10^-5*T+1000*2}{text{Solvefor}btext{where}}{b=a}

$$\left. \begin{array} { l } { {(T)} = -9 \cdot 10 ^ {-8} \cdot T ^ {3} + 9 \cdot 10 ^ {-6} \cdot T ^ {2} }\\ { a = -7 \cdot 10 ^ {-5} \cdot T + 1000 \cdot 2 }\\ { \text{Solve for } b \text{ where} } \\ { b = a } \end{array} \right.$$

Resolver T, a, b (complex solution)

$$T=0\text{, }a=2000\text{, }b=2000$$

$$T=\frac{50\sqrt{39991}i}{3}+50\approx 50+3332.958312237i\text{, }a=-\frac{7\sqrt{39991}i}{6000}+\frac{3999993}{2000}\approx 1999.9965-0.233307082i\text{, }b=-\frac{7\sqrt{39991}i}{6000}+\frac{3999993}{2000}\approx 1999.9965-0.233307082i$$

$$T=-\frac{50\sqrt{39991}i}{3}+50\approx 50-3332.958312237i\text{, }a=\frac{7\sqrt{39991}i}{6000}+\frac{3999993}{2000}\approx 1999.9965+0.233307082i\text{, }b=\frac{7\sqrt{39991}i}{6000}+\frac{3999993}{2000}\approx 1999.9965+0.233307082i$$

Resolver T, a, b

$$b=2000$$