Question 1089203
in 1 hour, they will both have swum 45 laps.


for jane:


y = 30 + 15x


for tarzan:


y = 20 + 25x


these 2 equations need to be solved simultaneously, meaning the same value of x solves both equations.


there are several ways to do this.


i'll use elimination this time around.


the 2 equations are:


y = 30 + 15x
y = 20 + 25x


the same value of y applies to both equations.
the same value of x applies to both equations.


this is because y represents the same number of laps that each will swim and x represents the same number of hours that each will swim.


subtract the second equation form the first to get:


0 = 10 - 10x


add 10x to both sides of the equation to get:


10x = 10


solve for x to get x = 10/10 = 1


jane has swum 30 laps and swims another 15 * 1 = 15 for a total of 45 laps.


tarzan has swum 20 laps and swims another 25 * 1 = 25 for a total of 45 laps.


solution looks good.


number of hours before the two have swum an equal number of laps is 1.