Question

(viii) 0.9x + 0.5y = 6; 00.7x + 0.7y = 5.6

Answer 1

$$\begin{gathered} 0.9x+0.5y=6 \\ \Rightarrow x=\frac{6-0.5y}{0.9}...\left(\mathrm{i}\right) \\ 00.7x+0.7y=5.6....\left(\mathrm{ii}\right) \\ \mathrm{Substituting}\mathrm{eq}\left(\mathrm{i}\right)\mathrm{in}\mathrm{eq}\left(\mathrm{ii}\right),\text{we get:} \\ 0.7\times \left(\frac{6-0.5y}{0.9}\right)+0.7y=5.6 \\ \Rightarrow 4.2-0.35y+0.63y=5.04 \\ \Rightarrow 0.28y=0.84 \\ \Rightarrow y=3 \\ \mathrm{Substituting}y=3\mathrm{in}\mathrm{eq}\left(\mathrm{i}\right),\mathrm{we}\mathrm{get}: \\ \Rightarrow x=\frac{6-1.5}{0.9} \\ \therefore x=5 \\ \mathrm{Hence},x=5,y=3\mathrm{is}\mathrm{the}\mathrm{solution}\mathrm{of}\mathrm{the}\mathrm{given}\mathrm{equations}. \end{gathered}$$