solve each of the following equations.㏒₇(9x+38) - ㏒₇(x+2) = ㏒₉81
Accepted Solution
A:
first you need to determine the defined range [tex] log_{7} [/tex](9x + 38) - [tex] log_{7} [/tex](x + 2) = [tex] log_{9} [/tex](81), x∈ (-2, + ∞)using the [tex] log_{a} [/tex](x) - [tex] log_{a} [/tex](y) = [tex] log_{a} [/tex] ([tex] \frac{x}{y} [/tex]), simplify the expression [tex] log_{7} [/tex] ([tex] \frac{9x+38}{x+2} [/tex]) = [tex] log_{9} [/tex](81) write the number in the second set of parenthesis in exponential form [tex] log_{7} [/tex] ([tex] \frac{9x+38}{x+2} [/tex]) = [tex] log_{9} [/tex] (9²) using [tex] log_{a} [/tex] ([tex] a^{x} [/tex]) = x, simplify the expression [tex] log_{7} [/tex] ([tex] \frac{9x+38}{x+2} [/tex]) = 2 the expression [tex] log_{a} [/tex](x) = b is equal to x = [tex] a^{b} [/tex] [tex] \frac{9x+38}{x+2} [/tex] = 7² evaluate the power [tex] \frac{9x+38}{x+2} [/tex] = 49 multiply both sides of the equation by x + 2 9x + 38 = 49(x + 2) distribute 49 through the parenthesis 9x + 38 = 49x + 98 move the variable to the left side and change its sign 9x - 49x + 38 = 98 move the constant to the right side and change its sign 9x - 49x = 98 - 39 collect the like terms -40x = 98 - 38 subtract the numbers -40x = 60 divide both sides of the equation by -40 x = -[tex] \frac{3}{2} [/tex], x ∈ (-2, + ∞) finally,, check if the solution is in the defined range x = -[tex] \frac{3}{2} [/tex] this means that the correct answer to your question is x = -[tex] \frac{3}{2} [/tex] let me know if you have any further questions :)