A classmate says that the expression -5r(6s) can be expanded to - 30r - 5rs. Explain his error ( WHOEVER ANSWER THEY GET 73 POINTS ! )

-5r(6s) would be -30rs because everything outside of the parentheses must be multiplied by everything inside the parentheses. -5r times 6s would be -30rs because -5 times 6 is thirty and when combining variables for an answer you would get rs whicg combine for -30rs

I'm not sure exactly but my best guess would be 1/4

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