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### Course: Digital SAT Math>Unit 8

Lesson 6: Isolating quantities: medium

# Isolating quantities — Harder example

Watch Sal work through a harder Isolating quantities problem.

## Want to join the conversation?

• At , can't we just raise 1 and r to the power of t?
that would mean:
1+r^t=A/P (Since 1^anything = 1)
therefore:
r^t=(A/P) - 1
giving:
r=((A/P)-1)

Just a question. I may be wrong but I think I need some clarification here.
• you know the formula for (a+b)^2,,,right
It contains a 2ab term
similarly ,a cubic equation contains a 3ab(a+b) term
Therefore,it's reasonable to infer that anything to the power of t would not contain isolated exponential sum of the individual terms.
Hope it helps :)
• tbh, i like this kinda isolating quantities problems. <3
• Hi all, wish you guys luck.
• At 1;20, why do you need to raise t to the 1 over t power?
• From the author:Great question! Sal is using a common method to simplify radical expressions. For example, if you have x^3 = 27, then you can take the cube root of both sides of the equation to solve for x. If you have learned about fractional exponents, remember that taking the cube root of something is the same as raising it to the (1/3) power. Similarly, taking the square root of something is the same as raising it to the (1/2) power. So, to cancel out the t power, Sal is raising both sides of the equation to the *(1/t)* power.
• anyone who has sat on nov
• These are so fun lowkey
• any other videos explaining this type of math? I have no idea whats going on
• my teachers taught me a whole different way to do the problem dealing with isolating quantities harder example. can someone please confirm what the recommended way to do this is?