When Angelo cashed a check for $170, the bank teller gave him 12 bills, some $20 bills and the rest $10 bills. How many bills of each denomination did Angelo receive?

5 $20 bills and 7 $10 bills

Step-by-step explanation:

You need to have 12 bills, and their values must add up to $170. Start with a guess, and adjust the guess until you find the answer.

The total number of $20 bills and $10 bills must be 10.

I made a table below. I started with a guess and kept adjusting it.

Number of          Number of          Total

$20 bills               $10 bills               Value

8   ($160)              4    ($40)              $200      Value is too high.

6   ($120)              6    ($60)              $180       Value is close

5   ($100)              7    ($70)               $70        Correct value

5 $20 bills and 7 $10 bills

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

24

step-by-step explanation:

the graph shows 30% of students walk. 80 students were questioned, so the number that said they walk is

30% × 80 = 0.30 × 80 = 24