Question

your friend rent 10chairs and 2 tables for $300. another friend rent 8 chairs and 4 tables for $360 you want to rent 12 chairs and 3 tables how much do you expect to pay? ps I need it today

Answer 1

$x-\ cost\ of\ renting\ chair\\ y-\ cost\ of\ renting\ table\\\\ \left \{ {{10x+2y=300\ \ \ \ \ \ \ \ \ \ \ \ } \atop {8x+4y=360\ \ \ | divide\ by\ -2}} \right. \\\\ \left \{ {{10x+2y=300} \atop {-4x-2y=-180}} \right. \\\\+----\\addition\\\\\ 6x=120\ \ \ | divide\ by\ 6\\\\ x=20\\\\ y=\frac{300-10x}{2}=150-5x=150-5*20=150-100=50\\\\ 12x+3y=12*20+3*50=240+150=390\\\\ I\ am\ expected\ to\ pay\ 390$