Question

Diketahui rumus f(x)=2x-5. jika f(k)= -15 maka nilai k adalah

Answer 1

F(x) = 2x-5
f(k) = -15

-15 = 2x-5
2x-5+15 = 0
2x+10 = 0
2x = -10
x = -10/2
x = -5

utk pembuktian
f(k) = 2x-5
= 2.-5 -5
=-10-5
=-15