Answer: #1: 7a-2#2: 6 3/7#3: -40/21Step-by-step explanation:For the first problem *the one for the perimeter of the triangle*, the perimeter of a triangle is just the three sides added up. If your problem wants us to write an equation, you'll have to add the three sides. Answer: (2a-3)+(3a+1)+2a which is (when you simplify it even further), 2a-3+3a+1+2a, and the answer is 7a-2.For the second problem *the one asking you for the value of x*, you know now that the perimeter of the triangle is 47 meters. This means, that a is an unknown number and you are solving for it. 7 times this unknown number plus 2 would be equal to 47. Equation: 7a+2=477a=47-27a=45a=45/7a= 6 3/7For the third problem, *the simplify fractions one*, you'll need to take the -4/3 out of the parentheses. If you do that, the + and the - will make a -. Now, the equation is: -4/7-4/3=?You need to find an LCM. In this case, it can be 21. [tex]\frac{4*3+4*7}{21}[/tex] You don't need to worry about the negative signs because when you have a negative minus a negative, the number increases. Now, your final answer will be -40/21.I hope this helps :D