Can someone plz fill in these coefficients  4., 5., 6., 7.

Start by balancing elements that don’t appear in single form. So, for number 4

Start by adding 2 to Cu2O to balance the oxygen

2Cu2O + C —-> Cu + CO2

Now the oxygen is balanced, but the Cu is not. This can now simply be mitigated by adding 2 to the single Cu

2Cu2O + C —-> 2Cu + CO2

That’s your final answer for #4