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This is a proportion. What is the value of X?

This is a proportion. What is the value of X?-example-1
User Lawana
by
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1 Answer

2 votes

Answer:

x = 15 or x = -
(2)/(5)

Explanation:

Cross- multiplying gives

(14x + 6)(17x + 5) = 9x(27x + 11) ( expanding factors )

238x² + 172x + 30 = 243x² + 99x

rearrange into standard form : ax² + bx + c = 0

5x² - 73x - 30 = 0 ← in standard form

consider the factors of the product 5 × - 30 = - 150 which sum to the coefficient of the x-term (- 73 )

the factors are - 75 and + 2

Use these factors to split the middle term

5x² - 75x + 2x - 30 = 0 ( factor by grouping )

5x(x - 15) + 2(x - 15) = 0 ← take out the factor (x - 15)

(x - 15)(5x + 2) = 0

equate each factor to zero and solve for x

x - 15 = 0 ⇒ x = 15

5x + 2 = 0 ⇒ x = -
(2)/(5)


User Shashank Shekher
by
6.7k points