He total temperature change over 5 days in Pretty City was −15 degrees Celsius. What was the average temperature change each day? (1 point)

−3 degrees Celsius
3 degrees Celsius
−10 degrees Celsius
10 degrees Celsius

9514 1404 393

  −3 degrees Celsius

Step-by-step explanation:

The average is the quotient of the total and the number of days:

  -15/5 = -3 . . . average change per day (units of °C)

< xcy ≅ < xby

step-by-step explanation:

in δcax and δbax,

so, δcax ≅ δbax (side-angle-side or sas)

since δcax ≅ δbax, we can conclude < acx ≅ < abx

in δacy and δaby,

so, δacy ≅ δaby (side-angle-side or sas)

since δacy ≅ δaby, we can conclude < acy ≅ < aby

now,

< acy ≅ < aby

=> < acx + < xcy ≅ < abx + < xby

=> < acx + < xcy ≅ < acx + < xby   (since < acx ≅ < abx already proved above)

subtracting < acx from both sides, we get

< acx + < xcy -< acx ≅ < acx + < xby -< acx

cancelling out < acx and -< acx from both sides, we get

< xcy ≅ < xby (proved)