Lesson 9

Write each subtraction equation as an addition equation.

1. $a-9 = 6$
2. $p-20=\text-30$
3. $z-(\text-12)=15$
4. $x-(\text-7)=\text-10$

Find each difference. If you get stuck, consider drawing a number line diagram.

1. $9 - 4$

2. $4 - 9$

3. $9 - (\text-4)$

4. $\text-9 - (\text-4)$

5. $\text-9 - 4$

6. $4 - (\text-9)$

7. $\text-4 - (\text-9)$

8. $\text-4 - 9$

Find the solution to each equation mentally.

1. $30+a=40$
2. $500+b=200$
3. $\text-1+c=\text-2$
4. $d+3,\!567=0$

A restaurant bill is $59 and you pay $72. What percentage gratuity did you pay?
 

One kilogram is 2.2 pounds. Complete the tables. What is the interpretation of the constant of proportionality in each case?