Question #6200018

# Help!!!Econometric question, thanks!!!!?

**Use F-test to test hypothesis H0:b1+b2=0 in model of y=constant+b1x1+b2x2+b3x3+e in program of Stata, this question I got it....but the following question: use t-test to test a model and generate a t statistics directly that also test the previous hypothesis.....
I'm really stuck with this quesiton......Thanks for any help!!!!!!!!!!!!!
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TELL US , if you have any answer