I am looking for help on how to isolate the variable. I don't want the answer to the entire problem just how to isolate the variable in order to solve.
Solve for x.
(5^x) + 7 = 50 - 3(5^x)
2007-04-10 12:32:00 · 5 answers · asked by rossiter_jenn 1 in Science & Mathematics ➔ Mathematics
5^x + 7 = 50 - 3(5^x)
4(5^x) = 43
5^x = 10.75
log 5^x = log 10.75
x log 5 = log 10.75
x = (log 10.75)/(log 5)
2007-04-10 12:36:35 · answer #1 · answered by Philo 7 · 0⤊ 0⤋
Solve for x.
(5^x) + 7 = 50 - 3(5^x)
The aim is to get the 5^x 's on one side of the equation and the numbers on the other side
Add 3(5^x) to both sides:
4(5^x) + 7 = 50
Take 7 from both sides:
4(5^x) = 43
Divide by 4:
5^x = 43/4
Take log[base 5]:
log[base 5](5^x) = log[base 5](43/4)
x = ln(43/4) / ln(5) = 1.476 (3 d.p.)
since log[base a](b) = log[base c](b) / log[base c](a)
2007-04-10 19:35:43 · answer #2 · answered by peateargryfin 5 · 0⤊ 0⤋
Add 3(5^x) to both sides and subtract 7 from both sides to get:
4(5^x) = 43
Then divide by 4 on both sides to get:
5^x = 43/4
Take the log base 5 to solve it
2007-04-10 19:36:38 · answer #3 · answered by Demiurge42 7 · 0⤊ 0⤋
Add 3(5^x) to both sides.
4(5^x) = 43
5^x = 43/4
2007-04-10 19:35:32 · answer #4 · answered by richardwptljc 6 · 0⤊ 0⤋
jsut move them over
(5^x) + 3(5^x) = 50 -7
4(5^x) = 43
5^x = 43/4
you can finish now I think
2007-04-10 19:36:28 · answer #5 · answered by hustolemyname 6 · 0⤊ 0⤋