If 18 : 6 = x : 3 then what is 5 + 3x

32

Step-by-step explanation:

18 :  6 = x : 3

Product of means  =  Product of extremes

6 * x = 3*18

     x =

     x = 3*3

x = 9

Now plugin x = 9 in the expression

5 + 3x = 5 + 3*9

          = 5 + 27

          = 32

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15