This "How do you solve x2−3x−28=0?" has been answered

Hailee Cline Answered2022-01-20

How do you solve

x^{2} - 3 x - 28 = 0

Answer & Explanation

Kaitlynn Noble

Expert

2022-01-21Added 12 answers

Step 1

x^{2} - 3 x - 28 = 0

We can first factorise this expression by splitting the middle term and then find the solutions:

= x^{2} - 7 x + 4 x - 28 = 0

= x (x - 7) + 4 (x - 7) = 0

= (x + 4) (x - 7)

Now, we can equate the two factors with zero and find the solutions:

x + 4 = 0, x = - 4

x - 7 = 0, x = 7

Anabelle Miller

Expert

2022-01-22Added 12 answers

Step 1
Solve

y = x^{2} - 3 x - 28 = 0

I use the new Transforming Method. Roots have different signs.
Factor pairs of

(c = - 28) \to (- 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.

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