since this is an inequality we need more than just the equal sign, but it can help to create a linear equation to get it. we only need to define one variable since they give us one, so what i will use is M=total money earned
M=350+25N
now simply replace your equation sign with the less than or equal to sign ([tex] \leq [/tex]) and the M with the 500 since Myra wants at least that.
500[tex] \leq [/tex]350+25N
now we must look for the least amount of times Myra needs to mow lawns, use the linear equation because exactly $500 is earned. this will be our M
500=350+25N
now take away 350 from each side so we can get N alone
150=25N
now divide each side to get N completely alone and that will give us the least amount of lawns Myra will need to mow to get to her goal
6=N, and since this was supposed to be an inequality replace the equal sign with the less than or equal to sign, 6[tex] \leq [/tex]N, or at least 6 lawns need to be mowed to get to Myra's goal
