How to use the method of decomposition of this trinomial and turn it into standard form:
0.005x^2 - 0.801x + 26.928
Don't be afraid of decimals, especially if you have access to a calculator.
0.005x^2 - 0.801x + 26.928 ..... factor out the coefficient of x^2 term from first two terms
= .005(x^2 - 160.2x + ..... - .....) + 26.928 .... take 1/2 of x term coefficient, square it, then add and subract it
= .005(x^2 - 160.2x + 6416.01 - 6416.01) + 26.928
write the first 3 terms in the bracket as a perfect square, we made them into such
= .005( (x - 80.1)^2 - 6416.01) + 26.928
distribute the .005 over the perfect square and the constant
= .005(x - 80.1)^2 - 32.08005 + 26.928
one more addition at the end
= .005(x - 80.1)^2 - 5.15205