Find the unknown value in the proportion: 9⁄x = 27⁄39 a. 6.2 b. 36 c. 38 d. 13

D. 13

Step-by-step explanation:

Multiply the given equation by 39x/27:

... x = 9·39/27 = 39/3

... x = 13

The usual approach

You may have learned to "cross multiply" to eliminate fractions. That means you multiply by the product of the denominators, 39x:

... 9·39 = 27x

Now, you divide by the coefficient of x, which is 27.

... 9/27 · 39 = x = 39/3 = 13 . . . . . . in the end, the same as above

the sum of the lengths of any two sides of a triangle is greater than the length of the third side. if you take the three sides of a triangle and add them in pairs, the sum is greater than (not equal to) the third side. if that is not true, then it is not possible to construct a triangle with the given side lengths.

step-by-step explanation:

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a