1.
a. 12d² -6d
b. 6c^5 + 8c^4 -10c³
c. correct
2.
a. correct
b. correct
c. 12r^8-6r^4 + 9r^2, then multiply the rest by -1
3. correct
4. x² + 10
5. d=4, -1/3
(2x² - 8x - 10) ÷ 2 = 0
x² - 4x - 5 = 0
x² + x - 5x - 5 = 0
x(x+1) - 5(x+1) = 0
(x+1)(x-5) = 0
x+1 = 0 or x-5 = 0
x = -1 or x= 5
S = {-1;5}
Answer:
true
Step-by-step explanation: In a concave polygon, each interior angle is less than 180°.