Sajia has 30 books in her library she sold 9 books at a thrift store on saturday write and solve an inquality to determine how many more books she can sell if she comes back on sunday

see the explanation

Step-by-step explanation:

Let

x ---->the number of books she can sell if she comes back on Sunday

y ----> the number of books sold on Saturday

we know that

The number of books sold on Saturday plus the number of books she can sell if she comes back on Sunday must be less than or equal to the initial number of books in the library (30 books)

so

The inequality that represent this situation is

we have

substitute

solve for x

subtract 9 both sides

therefore

The maximum number of books she can sell on Sunday is 21

the system of inequalities is

step-by-step explanation:

step 1

find the equation of the dashed line

we have the points

(0,0) and (3,1)

the line passes through the origin, so, is a direct variation

find the slope

the equation of the dashed line is

the solution of the inequality a s the shaded area above the dashed line

therefore

the equation of the inequality a is

step 2

find the equation of the solid line

we have the points

(4,0) and (0,4)

find the slope

the equation of the solid line is

the solution of the inequality b s the shaded area below the solid line

therefore

the equation of the inequality b is

step 3

the system of inequalities is

step-by-step explanation: