How do you solve #x^2- 3x - 28 = 0#?
The solutions are:
We can first factorise this expression by splitting the middle term and then find the solutions:
Now, we can equate the two factors with zero and find the solutions:
#x+4 =0, color(blue)(x=-4# #x-7 =0, color(blue)(x=7#
Solve y = x^2 - 3x - 28 = 0
I use the new Transforming Method (Google, Yahoo Search). Roots have different signs (Rule of Signs).
Factor pairs of (c = -28) -> (-2, 14)(-4, 7). This sum is 3 = -b. Then the 2 real roots are: -4 and 7.
NOTE. By this method, we can avoid the lengthy factoring by grouping and solving the 2 binomials.