A firm has a production function Q=F (K, L) with constant returns to scale. Input prices are r=$2/ K-unit and w=$1/L-unit. The output expansion path for this production function at these input prices is a straight line through the origin. When it produces 5 units of output, it uses 2 units of K and 3 Units of L. How much K and L will it use when its long-run total cost is equal to $70? How much will Q be? What is its LAC?