### u_n=2^(n-1)*(a+b)-b
def po(a,n,mod):
    res=a
    ans=1
    while(n):
        if(n%2):
            ans=ans*res%mod
        res=res*res%mod
        n=n//2
    return ans
def solve(a,b,n):
    mod = 1000000007
    b = b%mod
    a = a%mod
    mu = (n-1)%(mod-1)
    po2 = po(2,mu,mod)
    summ = (a+b)%mod
    anss = po2*summ%mod
    anss = (anss -b +mod) %mod
    print(anss)
testcase = int(input())
while(testcase>0):
    aa = list(map(int,input().split()))
    a = aa[0]
    b = aa[1]
    n = aa[2]
    solve(a,b,n)
    testcase=testcase-1
 
 

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MwoxIDIgMwozIDIgMQoxIDEgMg==

3
1 2 3
3 2 1
1 1 2