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5 votes
What are the solutions to the equation?
x² + 3x - 54​

2 Answers

6 votes

Answer:

(x+6)⋅(x−9)

Step by Step

Factoring x2-3x-54

The first term is, x2 its coefficient is 1 .

The middle term is, -3x its coefficient is -3 .

The last term, "the constant", is -54

Step-1 : Multiply the coefficient of the first term by the constant 1 • -54 = -54

Step-2 : Find two factors of -54 whose sum equals the coefficient of the middle term, which is -3 .

-54 + 1 = -53

-27 + 2 = -25

-18 + 3 = -15

-9 + 6 = -3 That's it

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -9 and 6

x2 - 9x + 6x - 54

Step-4 : Add up the first 2 terms, pulling out like factors :

x • (x-9)

Add up the last 2 terms, pulling out common factors :

6 • (x-9)

Step-5 : Add up the four terms of step 4 :

(x+6) • (x-9)

Which is the desired factorization

User Malarzm
by
3.9k points
3 votes

Answer:

x = - 9, x = 6

Explanation:

Given

x² + 3x - 54

To find the solutions equate to zero

x² + 3x - 54 = 0 ← in standard form

(x + 9)(x - 6) = 0 ← in factored form

Equate each factor to zero and solve for x

x + 9 = 0 ⇒ x = - 9

x - 6 = 0 ⇒ x = 6

User Thomas Braun
by
4.4k points