Solve for x algebraically Give exact solutions where necessa
Solve for x algebraically, Give exact solutions, where necessary,
a. 8 = 4^x^2 (4 is to the power of x squared (x^2)) multiplied by 2^5x
b. 9^x + 4 multiplied by 3^x - 3 = 0
c. log6 (x+3) + log6 (x+4) = 1
Solution
a) 8 = (4^x^2).(2^5x)
2^3 = (2^2x^2).(2^5x)
2^3 = (2^(2x^2 +5x))
3 = 2x^2 +5x
2x^2 +5x -3=0
2x^2 +6x-x -3=0
2x(x+3) -1(x+3)=0
(2x-1) (x+3) =0
so x=1/2 or x=-3
b).
(9^x +4).(3^x -3)=0
so (9^x +4) =0 or (3^x -3)=0
3^x =3
xlog3 =log3
x =1 is solution
c).
log6 (x+3) + log6 (x+4) = 1
log6 (x+3)(x+4) =1
(x+3)(x+4) =6^1
(x^2 +7x +12 =6
x^2 +7x+6=0
x^2+6x+x+6=0
x(x+6) +1(x+6) =0
(x+6)(x+1) =0
so x =-6 or x=-1
but x=-1 we get sloution
