jika diketahui rumus f(x)=5x-3 .jika f(a)=-13 dan f(-4)=b maka nilai a-b adalah...

f(a) = 5a-3
-13 = 5a-3
5a = -10
a = -2

f(-4) = 5(-4)-3
b = -20-3
b=-23

nilai a-b = -2-(-23) = 21

f(x) = 5x - 3

dik: f(a) = -13
f(-4) = b
dit: a-b?

f(x) = 5x - 3
f(a) = 5(a) - 3
-13 = 5(a) - 3
5(a) = -3 + 13
5(a) = 10
a = 10/5
a = 2

f(b) = 5(-4) - 3
f(b) = -20-3
f(b) = -23

a-b
2-(-23)
= +25