Tìm x biết a/2525:x=25 b/4x+4=20 c/84-4.(x+3)=44 d/3.2 mũ x+2=4 mũ 3-50

a/2525÷x=25 x=2525÷25 x=101 b/4x+4=20 4x =20-4 4x =16 x =16÷4 x =4 c/84-4(x+3)=44 4(x+3)=84-44 4(x+3)=40 x+3=40÷4 x+3=10 x =10-3 x =7 d/3×2^x+2=4^3-50 3×2^x+2=64-50 3×2^x+2=14 3×2^x =14-2 3×2^x =12 2^x =12÷3 2^x =4 2^x =2^2 => x = 2