Write the LCD (Least Common Denominator I think) for each pair of fractions. 1/3, 1/5 | 2/7, 1/4 | 3/4, 3/5 | 2/9, 5/12 | 1/3, 3/7 | 1/6, 4/9

Please help. ASAP

A)a square brown tarp has a square green patch green in the corner the side length of the tarp is (x + 8) and the side length of the patch is x what is the area of the brown part of the tarpb)a square red placemat has a gold square in the corner the side length of the gold square is (x - 2) inches with the width of the red region is 4 in what is the area of the red part of the placemat