Lydia started collecting seashells when she was five years old. At age seven, Lydia had 12(10)² seashells. At age nine, Lydia had 24(10)²seashells. At age eleven, Lydia had 48(10)² seashells. Lydia wants to collect 75(10)³ seashells. Lydia continues to collect seashells at the same rate. How old will Lydia be when she has 75(10)³ seashells? Show all your mathematical thinking. Lydia will be 13 when she has 75(10)

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,

30005

yes ok                                            

the image is given below

since the options are not given so we draw it from the equation

the given equation is

y = (x-1) (x+4)

y = y² + 3x - 4

the above equation is a quadratic equation which will have two roots. if we draw the graph for it, it will look like this