Question

alguém sabe fazer os exemplos (a,b,c,d)?

Answer 1

a) 5^x=125
5^x=5^3
x=3
b) 11^(x-2)=1
11^(x-2)=11^0
x-2=0
x=0+2
x=2
c) 3^x(x+2)=27
3^(x^2+2x)=3^3
x^2+2x=3
x^2+2x-3=0
delta=b^2-4ac
delta=2^2-4.1.(-3)
delta=4+12
delta=16
x=-b-/+ raiz de delta/2a
x=-2-4/2.1
x=-6/2
x=-3
x=-2+4/2.1
x=2/2
x=1
d) 5^2x-4.5^x+3=0
5^2.5^x-4.5^x+3
25.5^x-4.5^x+3
125^x-4.5^x+3
(5^3)^x-4.5^x+3
y^3-4.y+3
y^3-4y+3
y.(y-4)+3
y^2-4y+3=0
delta=b^2-4ac
delta=(-4)^2-4.1.3
delta=16-12
delta=4
y=-b-/+ raiz de delta/2a
y=-(-4)-2/2.1
y=4-2/2
y=2/2
y=1
y=-(-4)+2/2.1
y=4+2/2
y=6/2
y=3