A=h(b1+b2)/2, where A is the area of the trapezoid, H is the height, and B1 and B2 are the lengths of the bases. use the formula to find B1 if H is 7 meters, B2 is 10.5 meters, and A is 96.25 square meters. show ur work. ( ik its a lot but I could really use the help, 15 points)