Iam struggling with these three questions. if you could answer one or more it would be great : )

Hey there! :D

Plug in the solution. 

5(2) + 2(-3)=4 || 10-6=4 || 4=4 <== true

4(2) + -3= 11    || 8-3= 11 ||  5=11 <== not true

4. is not a solution. 

3(1)+2(5)=13  ||  3+10=13 || 13=13 <== true

4(1)-3(5)=-11   || 4-15=-11 || -11=-11 <== true

5. is a solution 

2(-6) - 5(-2)=-22 || -12+10=-22 -2=-22 <=== not true

6. is not a solution 

I hope this helps!
~kaikers

The surface area would be 576 because you multiply all the numbers then multiply that number by 6