Use what you know about the properties to rewite each number sentence. use mental math to find the sum. 0.6 + (0.4 + 0.9) = n and (1.57 + 0.75) + 0.25 + n

First Equation:

0.6 +(0.4+0.9) =n

Step 1: do parentheses first:  

0.4+0.9 = 1.3

Step 2: Add 0.6 + 1.3

0.6 + 1.3 = 1.9

n= 1.9

Second Equation:

(1.57 + 0.75) + 0.25 + n

Step 1: do parentheses first:

1.57 + 0.75 = 2.50

Step 2: Add 2.50 + 0.25 = 2.75

Step 3: Add 2.75 and n = 2.75+n

Final

1.9 +2.75+n = 4.65 +n

Hope this helps!!

1696 hundred thousand

step-by-step explanation:

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.