Aratati ca urmatoarele functii sunnt injective: a)f:R -R, f(x)=x+7
b)f:R-R, f(x)=2x
c)f:R-R, f(X)= -3x+1

b mark me branliest thx

step-by-step explanation:

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.

p

step-by-step explanation: