Match the expressions with the nonpermissible replacements for y.

Question

y2−2y+12y−3

y(y+5)4y+1

5y2−6y+1-5(y−1)

y2−y−6-2(y+7)

 

Options per answer:

-7, 3/2, 1, -1/4

Answer 1

The y substitutions for each expression are:

{-24 14.25 8 -5.4375}, {-391 59.5 25 2.1885}, {328 0.75 0 9.0625}, {50 -22.25 -22 -19.1875}

I've interpreted y2 (small 2) as y^2 in the expressions. I've also interpreted y(y+5)4y+1 as (y*(y+5)*4y)+1. There appear to be no square roots or divisions in the expressions, so all can be evaluated with each of the four values of y given. There are no non-permissible values for y. The 4 sets above show the results of substituting the four y values into each expression. There is only one expression producing a value of zero and that is y=1 for expression 3. There is only one set (3rd expression) giving all positive values for the expression. The others contain mixtures of positive and negative values, the 4th expression containing the most negatives.