5th grade. ( my little sister)
Answer:
50+50=100
100+100=200
Step-by-step explanation:
The sum of 2 numbers is 100. 50 x 2 = 100
Twice the first number plus twice the second number is 200.
50+50=100 so therfore 100+100 makes 200
Perimeter of a triangle = all 3 sides added together
x + (x - 4) + (x - 4) = 19
3x - 8 = 19
3x = 19 + 8
3x = 27
x = 27/3
x = 9 <==
if x = 3
3 > -1, and so you use the x² formula.
Plug in 3 for x
x² = (3)²
Simplify
3² = 3 x 3 = 9
9, or (A), is your answer
hope this helps