Write each expression in standard from verify that your expression is equivalent to the one given by evaluating each expression using x =5 a) 3x + (2 - 4x)
b) 3x + (-2 + 4x)
c) -3x + (2 + 4x)
d) 3x + (-2 - 4x)
e) 3x - (2 + 4x)
f) 3x - (-2 + 4x)
g) 3x - (-2 - 4x)
h) 3x - (2 - 4x)
i) -3x - (-2 - 4x)
PLEASE HELP ME!!! I DONT UNDERSTAND!

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?