Question

encontre o valor de k: ( k - 3) × 2 ² - ( k + 4 ) × 2 +6

Answer 1

(k - 3) x 2² - (k + 4) x 2 + 6 =
( k - 3 ) x 4 - (2 k + 8 ) + 6 = 
4 k - 12  - 2 k - 8 + 6 =
4 k - 2 k - 12 - 8 + 6 =
2 k -20 + 6 =
2 k  - 14 = 
2 k = 14 
k = 14/2
k = 7