4-3 Write and Solve Addition/Subtraction Equations

How can you use the inverse relationship to solve the following equation.

 $n+7=25$  

• add 7 to both sides

• subtract 7 from both sides

Answer explanation

Addition and subtraction are inverse operations.

Clare had t seashells. After she bought 8 more seashells, she had 24 seashells. Write the equation and solve for t.

• $t-8=24:\ t=32$

• $t+8=24:\ t=16$

The outside temperature dropped 20°F from the time Arianna ate breakfast until the time she ate dinner. When

she ate dinner the temperature was 35°F. Write and solve the equation for the temperature, t, when Arianna ate breakfast.

• $t-20=35:\ t=55$

• $t+20=35:\ t=15$

• $t-20=35:\ t=37$

 $24+m=49:\ m=?$  

Answer explanation

Subtract 24 from both sides.

 $12=y-11$  

Answer explanation

Add 11 to both sides.

 $22=13+a:\ a=?$  

Answer explanation

Subtract 13 from both sides.

 $t-40=3:\ t=?$  

Answer explanation

Add 40 to both sides.

 $d+11=15:\ d=?$  

Answer explanation

Subtract 11 from both sides.

 $32=s-19:\ s=?$  

Answer explanation

Add 19 to both sides.

 $25+v=45:\ v=?$