1. anonymous

You have to use the first two equations to find x and y, then use this answer to solve the last equation. $5x+4y=21 ...(1)$$x+y=9...(2)$From (2), we have y = 9 - x. Substitute this into (1) to obtain$5x+4(9-x)=21 \rightarrow 5x+36-4x=21 \rightarrow x = -15$If x = -15, we can use the result from (2) to obtain $y=9-x=9-(-15)= 24$ Hence,$6x+5y=6(-15)+5(24)=30$

2. anonymous

Thank You

3. anonymous

You're welcome

4. anonymous

^^ Same here :)