What numbers multiply to 29 and add to 100

(a) compute the maclaurin polynomial m2(x) for f(x) = cos x. (b) use the polynomial of part (a) to estimate cos π 12. (c) use a calculator to compute the error made using the estimate from part (b) for the value of cos π 12. remember that the error is defined to be the absolute value of the difference between the true value and the estimate.

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

How is working backward similar to solving an equation?