Question

Givenf (x) = 2x – 10 forwhichvalueofäthat f (x) = 8?
Answers are -12, 18,6,5

Answer 1

see below

Explanation:

f (x) = 2x – 10

Let f(x) = 8

8 = 2x-10

Add 10 to each side

8+10 =2x-10+10

18 =2x

Divide by 2

18/2 = 2x/2

9 =x

If you mean

f(8) = ?

Let x=8

f(8) = 2*8-10

= 16-10

= 6

f(8) = 6

Answer 2

9

Explanation:

f(x) = 2x - 10

8 = 2x - 10

18 = 2x

9 = x

Best of Luck!