F(x)= 18x^2+15x-10 find x when f(x) =15

Step-by-step explanation:

f(x) is simply another way of saying y

We are told that y = 15, so we set the equation 18x² + 15x - 10 equal to 15.

Add 10

18x² + 15x = 25

18x² + 15x + 25 = 0

Factor

(6x − 5) (3x + 5) = 0

Find both solutions for x

6x - 5 = 0

6x = 5

x = 5/6

Now, for the other solution.

3x + 5 = 0

3x = -5

x = -5/3

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47