Question

Va rog din suflet sa ma ajutati.Ofer 26 de punctee va rog mult.
1.Determinati multimea A={x ∈ Z / -5 supra 2x+3 ∈ N}
2.Numerele a si b sunt respectiv direct proportionale cu 2 si 5.Cat la suta reprezinta nr a din nr b ?
3.Calculati :(I3⁷⁵-5⁵⁰I+25²⁵):9³⁷

Answer 1

1) 2x+3∈{-5,-1,1,5}
2x+3=-5⇒ 2x=-5-3⇒x=-4
2x+3=-1⇒2x=-1-3⇒x=-2
2x+3=1⇒2x=1-3⇒x=-1
2x+3=5⇒2x=5-3⇒x=1
A={-4,-2,-1,1}

2){a,b}dp{2,5}
a/2=b/5=k
a/2=k⇒a=2k
b/5=k⇒b=5k