Answer:
20
Explanation:
Evaluate 3 x^2 - 4 x where x = -2: 
3 x^2 - 4 x = 3×(-2)^2 - -2×4 
 
Hint: | Evaluate (-2)^2. 
(-2)^2 = 4: 
3×4 - 4 (-2) 
 
Hint: | Multiply 3 and 4 together. 
3×4 = 12: 
12 - 4 (-2) 
 
Hint: | Multiply -4 and -2 together. 
-4 (-2) = 8: 
8 + 12 
 
Hint: | Evaluate 12 + 8 using long addition. 
 | 1 | 
 | 1 | 2 
+ | | 8 
 | 2 | 0: 
Answer: 20