Tania lived in columbia and dominican republic for a total period of 14 months in order to learn spanish. she learned an average of 130 new words per month when she lived in columbia, and an average of 150 new words per month when she lived in the dominican republic. in total, she learned 1,920 new words. select two equations that could be used to model the situation.
a
130c + 150d = 1400

b
c + d = 14

c
130c + 150d = 1920

d
14c + 14d = 1920

Step-by-step explanation:

If we define the variables c and d to represent the number of months spent in Columbia and Dominican Republic, respectively, then we can write equations for the total number of months and the total number of words:

  c + d = 14 . . . . . . . . . . . . total number of months

  130c +150d = 1920 . . . . total number of words

Comment on the problem

Before you can write equations, you need to define the variables. The problem statement does not do that, so just about any of the equations could be argued to be correct for some definition of the variables.

option 3 . (5x + 1) - (-10x + 6)

step-by-step explanation:

option 1 :

(4x + 3) + (-9x + 4)

or 4x+3 -9x + 4

or -5x + 7

option 2

(x - 2) - (6x - 9)

or x-2-6x + 9

or -5x + 7

option 3

(5x+ + 6)

or 5x + 1 + 10x -6

or 15x -5

option 4

-4x+2x+7-3x

-7x + 2x + 7

-5x + 7

hence only option 3 did   not satisfy the given simplify expression.