Estimation is a important skill to know when adding and subtracting decimals because if you estimate you have an idea on what your answer should be close to.
For example 4.68-2.38 could be 5-2 which is 3. 4.68-2.38 equals 2.3. 2.3 is close to 3.
-3.
Coefficients are numbers that have a variable next to it, thus leading it to be -e of the -3x.
Hope this helps!
We have the formula S= r * theta , where S is arc length , r is radius , and theta is central angle in radians
So AB= 4 * 45* π/180 = π units
