Question

Simplify: (−7a − 19c) − (−12a + 30c) − (−21a − 11c)

Answer 1

2*(13a-19c) hope that helps for you 

Answer 2

(−7a − 19c) − (−12a + 30c) − (−21a − 11c)

= −7a − 19c + 12a - 30c + 21a + 11c

= (-7a + 12a + 21a) + (11c - 19c - 30c)

= 26a - 38c

= 2(13a - 19c)