Write a decimal addition problem that requires regrouping the hundredths. explain how you know you will need to regroup

The answer is provided as a whole explanation

Step-by-step explanation:

Regrouping is the presentation of a number or decimal with its number groups. For example, we can represent 0.25 in this way:

0.25 = 0.2 + 0.05

0.25 = 2 tenth + 5 hundredth  

We can also write 0.25 as:

0.25 = 0.1 + 0.15

0.25 = 1 tenth + 15 hundredth

Regrouping is handy to simplify a mathematical calculation since we know how many tenth or hundredth we have got in this case.

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.