This Excel LAMBDA function taxes a table of incremental tax brackets and a known tax amount and calculates the income that would produce that tax amount.

excel-lambda-GETSALARYFROMTAX.txt

GETSALARYFROMTAX = LAMBDA(low, high, rate, 
    LAMBDA(tax,
        LET(
            diff, high - low,
            bracketmax, diff * rate,
            runsum, SCAN(0, bracketmax, SUM),
            XLOOKUP(
                tax, 
                runsum, 
                low + diff * (tax - runsum + bracketmax) / bracketmax, 
                , 
                1 // Match or next largest item
            )
        )
    )
);