1: What divides evenly into 3`y`^{2} – 21`y` + 36?

5: Start by factoring out 4 from each term.

12: To split -31 into two numbers that multiply to equal a positive product, both numbers must be negative.

14: To split the middle term into two terms that multiply to equal a negative product, one must be positive and one must be negative.

15: See the hint for #5 and for #14.

23: 2(`x`^{2} – 2`x` – 24) would equal 2`x`^{2} – 4`x` – 48, not 2`x`^{2} – 2`x` – 24.

26: Factor the expression, and then set each factor equal to zero.

29: The value of `y` is 0 where the graph crosses the `x`-axis.

40: If two factors multiplied together equals zero, then one of the factors must equal zero.