problem using data validation and vlookup; using 2 inputs to get 1 value

Basically i have 2 drop down menus with slope and Rmax in each. In Rmax there is the option of Rmax37 and Rmax99.

What I need is a a function where i select say “slope 1 in 1 and Rmax37” the value for coefficient A=0.00703 pops in a cell, the same for Rmax99 where if i select 1 in 1 and Rmax99 0.00515 appears in the cell.
i would like the same for the cofficient B.

I have a table as such below

Slope Rmax37 Rmax99

1 in 1 A 0.00703 0.00515
B 3.42 6.06

1 in 2 A 0.00753 0.00542
B 4.17 7.16

1 in 3 A 0.0104 0.00922
B 6.27 10.96