the pressure (p) that a 160-pound person's shoe exerts on the ground when walking varies inversely with area (a) of the sole of the shoe. when the shoes have a sole area of 40 sq. in., the pressure is 4 pounds per sq. in. what is the sole area of the sole when the pressure is 10 pounds per sq. in. ?

Answer 1

we know that p*a = k
also, 4*40 = k = 160

so, 10*a = 160
. . .

Answer 2

3x+y=20 x+3y=12