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Solve the equation 5q2 + 18q = 35

1 Answer

1 vote

Answer:

q = - 5 , q =
(7)/(5)

Explanation:

5q² + 18q = 35 ( subtract 35 from both sides )

5q² + 18q - 35 = 0 ← in standard form

consider the factors of the product of the coefficient of the q² term and the constant term which sum to give the coefficient of the q- term

product = 5 × - 35 = - 175 and sum = + 18

the factors are + 25 and - 7

use these factors to split the q- term

5q² + 25q - 7q - 35 = 0 ( factor the first/second and third/fourth terms )

5q(q + 5) - 7(q + 5) = 0 ← factor out (q + 5) from each term

(q + 5)(5q - 7) = 0 ← in factored form

equate each factor to zero and solve for q

q + 5 = 0 ( subtract 5 from both sides )

q = - 5

5q - 7 = 0 ( add 7 to both sides )

5q = 7 ( divide both sides by 5 )

q =
(7)/(5)

solutions are q = - 5 , q =
(7)/(5)

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