Question

Can someone plz show me how to solve this

Answer 1

Check the picture below.

in the rectangle, all sides meet at right-angles, that makes the two pairs of sides a pair of two equal sides.  So the left and right are equal and top and bottom are also equal, as in the picture below.

$\bf \begin{cases} 12y+10=10x\\ 6x+3=9y \end{cases}\\\\ -------------------------------\\\\ 12y+10=10x\implies 12y=10x-10\implies y=\cfrac{10x-10}{12} \\\\\\ y=\cfrac{10x}{12}-\cfrac{10}{12}\implies y=\cfrac{5x}{6}-\cfrac{5}{6}\implies \boxed{y=\cfrac{5x-5}{6}}\\\\ -------------------------------\\\\ \textit{now, substituting in the \underline{second function}}$

$\bf 6x+3=9\left( \boxed{\cfrac{5x-5}{6}} \right) 6x+3=3\cdot \cfrac{5x-5}{2} \\\\\\ 6x+3=\cfrac{15x-15}{2}\implies 12x+6=15x-15\implies 21=3x \\\\\\ \cfrac{21}{3}=x\implies \boxed{7=x}\\\\ -------------------------------\\\\ \textit{now, we know that }y=\cfrac{5x-5}{6}\implies y=\cfrac{5(7)-5}{6} \\\\\\ y=\cfrac{35-5}{6}\implies y=\cfrac{30}{6}\implies \boxed{y=5}$