A rectangular room measures 3.8 meters in length and 4.9 meters in width. Jana multiplies both numbers together. Which expression would be best for her to use to check the reasonableness of her decimal multiplication?

Step-by-step explanation:

"A rectangular room measures 3.8 meters in length and 4.9 meters in width. Jana multiplies both numbers together. Which expression would be best for her to use to check the reasonableness of her decimal multiplication?"

given that

the length is 3.8m long and,

width is 4.9m wide

The expression for the area is

Area= length * width

Area= 3.8*4.9

Area= 18.62 m^2

Therefore the expression best for her to use to check the reasonableness of her decimal multiplication is the area which is  18.62 m^2

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10