Simplify 5a + 4b + 5c + (-2a) + b a.3a + 4b + 5c
b.3a + 5b + 5c
c.7a + 5b + 5c
d.12abc

its muilty chose ^^ so its a, b,c, or d
please help

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post

D. triangular pyramid