Question

(-2a) ^4+2a(-2a) ^3+5(-2a) ^2+9?(-2a) +18-20a^2​

Answer 1

Answer:

a = -1

Step-by-step explanation:

$( - 2a)^{4} + 2a( - 2a)^{3} + 5( - 2a)^{2} + 9( - 2a) + 18 - 20a^{2} \\ = 16a^{4} + 2a( - 8a^{3}) + 5(4a^{2}) - 18a + 18 - 20a^{2} \\ = 16a^{4} - 16a^{4} + 20a^{2} - 18a + 18 - 20a^{2} \\ = - 18a + 18 \\ - 18a = 18 \\ a = \frac{ - 18}{18} \\ a = - 1$