fungsi f dinyatakan dgn rumus f(x) =ax+b,jika f(2)=13 dan f(5)=22 maka rumus fungsi f(x) adalah?? Tolong bantuannya

f(x) = ax + b
f(2)= 2x + b = 13
f(5)= 5x + b = 22
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-3 x = -9
x = 3
2x + b = 13
2(3)+ b = 13
6 + b = 13
b = 13 - 6
b = 7
rumus fungsi...
f(x) = ax + b
f(x) = 3x + 7