Question

A={x apartine N, 5 la puterea × mai mic sau egal 625
B= { x| x apartine N,(7 la puterea 0 + 1 la puterea 1999+ 1 la puterea 2000+ 1 la puterea. 2001)× mai mic ca 64}

Answer 1

5^x≤625
5^x≤5⁴
x≤4
A={0,1,2,3,4}

(7⁰+1¹⁹⁹⁹+1²⁰⁰⁰+1²⁰⁰¹)^x<64
(1+1+1+1)^x<2⁶
4^x<2⁶
2^2x<2⁶
2x<6
x<6/2
x<3
B={0,1,2}

Answer 2

5^4=625;A={0,1,2,3,4}
7^0=1,
1 la orice putere este 1
1+1+1+1=4
4^3=64
B={0,1,2,}
A={0,1,2,3,4}