arianna's mom deposits $80 in her lunch account. Lunch costs $2.50 per day. Write and solve an inequality to determine when there will be less than $20 in her account.
I'm not sure how to set this up. would i subtract $80 to add it back to $20 on the other side of the inequality sign?
To set up the inequality, let's first define a variable. Let's say x represents the number of days Arianna has used for lunch.
Since lunch costs $2.50 per day, the amount of money spent on lunch after x days will be 2.50x.
The original deposit in her lunch account is $80. So, the amount of money remaining in her account after x days of lunch would be 80 - 2.50x.
To find when there will be less than $20 in her account, we need to set up an inequality:
80 - 2.50x < 20
Now, let's solve the inequality to determine the maximum number of days that Arianna can purchase lunch before her account balance drops below $20.
Subtract 80 from both sides, and we get:
-2.50x < 20 - 80
Simplifying further gives:
-2.50x < -60
To isolate x, we need to divide the entire inequality by -2.50. However, when dividing an inequality by a negative number, we need to reverse the inequality symbol:
x > -60 / -2.50
After simplifying, we get:
x > 24
Therefore, Arianna will have less than $20 in her lunch account after 24 days of purchasing lunch.
to find y-intercept set x = 0
= -10(0) + 5y = 40 since -10(0) = 0
= 0 + 5y = 40
=> 5y = 40 divide both sides by 5 to get the value of Y
=> y = 40/5 = 8
=> the y-intercept for the above equation is 8
to find x-intercept set y=0
= -10x + 5(0) = 40 since 5(0) = 0
= -10x = 40 divide both sides by -10 to find X
=> x = 40/-10 = -4
=> the x-intercept for the above equation is -4
Yes.
80 - 2.5x > 20