
William W. answered 09/29/21
Math and science made easy - learn from a retired engineer
Use synthetic division to divide x3 - 11x2 + 49x - 75 by "x - 3" Note that "x - 3" is equivalent to a zero of x = 3
To use synthetic division:
Set up the division by putting the "zero" to the left and the coefficients of the polynomial to the right. Like this:
Bring down the "1" and multiply 3 times 1 and put the result (3) below the "-11" then add them. Put the answer (-8) below the line. Now, multiply 3 times -8 and put the result (-24) under the "49" and add them. Put the answer (25) below the line. Now multiply 3 times 25 and put the result (75) under the "-75" and add them. Put the answer (zero) below the line. Like this:
If you get zero as the last result (like you did here) then the remainder is zero and "x - 3" divides evenly into x3 - 11x2 + 49x - 75. The result (quotient) is coded in the numbers below the line which are 1, -8, and 25 (ignore the zero). Starting with an "x" that is one degree less than the highest degree in the original polynomial), add "x" values in decreasing order to the numbers. So, since you started with x3 in your original polynomial, the quotient will start with x2 so 1x2 - 8x + 25 or just x2 - 8x + 25.
Now, to find the other zeros, solve x2 - 8x + 25 = 0 using the quadratic formula.