An airplane started at point X, traveled 320 miles to point Y, adjusted its route,

67.88°

Step-by-step explanation:

If three sides of a triangle are known and you want to determine one angle, this can be done using cosine rule.

Given sides x, y, and z and the angle Y is opposite to side y, the cosine formula is given as:

y² = x² + z² - 2xzcosY

For this problem, x = 400 miles, y = 599 miles, z = 320 miles.

Using the cosine formula:

Degree to adjust its route at point Y = 180° - 112.12° = 67.88°

It needs to adjust by 67.88° at point Y

The answer to the sum 3568 × 39610 =141 328 480, so neither of them correct

both tried to use partition method to multiply the two numbers but neither of them has  partitioned the values correctly

3568 = 3000+500+60+8
39610 = 3+9000+600+10

then we multiply in turn each value from 3568 to the values of 39610
3000  × 3
3000  × 9000
3000  × 600
3000  ×10 

and so on