Question

2) Tìm x:

a)(-5)^2 - (5x - 3)= 4^3

b)3x -17=x+3

c)5^x +5^x+2 = 650

AI NHANH MÌNH TICK CHO :)

Answer 1

2

a,\(\left(-5\right)^2-\left(5x-3\right)=4^3\)

=>25-5x+3=64

=>25+3-64=5x

=>-36=5x

=>x=-36:5

=>x=-7,2

b,3x-17=x+3

=>3x-x=17+3

=>2x=20

=>x=20:2

=>x=10

Answer 2

c,\(5^x+5^{x+2}=650\)

=>\(5^x+5^x.5^2=650\)

=>\(5^x+5^x.25=650\)

=>\(5^x.\left(1+25\right)=650\)

=>\(5^x.26=650\)

=>\(5^x=650:26\)

=>\(5^x\)=25

=>\(5^x=5^2\)

=>x=2