how do i do these problems

Question

how do i simplyfy this expresion 

a + a =

 

 

hannah went up 340 feet while hicking if hannah started at 100 feet below sea level what integer represents her elevation now 

 

what is the area of a square whose sides each measure 5 feet long 

 

25 ft²

20 ft2

50 ft2

 10 ft²

Answer 1

1. Forget about the a. Make it simple. Pretend a is 1.

    1 + 1 = 2

    Now a + a there are TWO a's there. So an a plus a second a is going to be 2a's
    a + a = 2a

 

2. Hannah WAS at 100 feet below sea level. In a numerical form, this would be -100 ft. -100 + 340 = 240 ft

3. If the shape is a square, each side is the same length, meaning each side is 5 ft long. The area of a square of rectangle is length x width. This means the area of this square is 5 x 5 = 25 sq ft