Step-by-step explanation:
[tex]\left\{\begin{array}{ccc}y=\dfrac{3}{4}x&(1)\\\dfrac{5}{2}x+2y=5&(2)\end{array}\right\\\\\text{substitute (1) to (2)}\\\\\dfrac{5}{2}x+2\left(\boxed{\dfrac{3}{4}x}\right)=5\\\\\dfrac{5}{2}x+\dfrac{6:2}{4:2}x=5\\\\\dfrac{5}{2}x+\boxed{\dfrac{3}{2}x}=5\qquad|\text{combine like terms}\\\\\dfrac{5+3}{2}x=5\\\\\dfrac{8}{2}x=5\\\\\boxed{4x=5}\qquad|\text{divide both sides by 4}\\\\\dfrac{4x}{4}=\dfrac{5}{4}\\\\\boxed{x=\dfrac{5}{4}}[/tex]
[tex]\text{Put it to (1):}\\\\y=\dfrac{3}{4}\left(\boxed{\dfrac{5}{4}}\right)\\\\y=\dfrac{3\cdot5}{4\cdot4}\\\\y=\boxed{\dfrac{15}{16}}[/tex]
