It's linear
If you evaluate x when it's 0 you'll get the cut in y, that means the function will pass on (0,7)
The formula for linear functions is y=mx +b
In this case b is 7
M=7-5/0+1
M=2
Now you just write the function down, it would be
F(x) =2x + 7
2,3 I think that’s the answer
In paraller connection you can calculate the equivlant resistqnce from the relation :
1/R(equi) = 1/R1 + 1/R2 + 1/R3
1/R(equi) = 1/20 +1/20 + 1/10
1/R(equi) = 0.05+0.05+0.1 = 0.2
so, R(equi) = 5 ohms