Question

Sven is trying to find the maximum amount of time he can spend practicing the five scales of piano music he is supposed to be working on. He has 70 minutes to practice piano and would like to spend at least 55 minutes playing songs instead of practicing scales. So, Sven sets up the following inequality, where t is the number of minutes he spends on each scale, and solves it.
70 − 5t ≤ 55
−5t ≤ −15
t ≥ 3


Sven has concluded that he should spend 3 minutes or more on each scale. Is this correct? If not, what mistake did he make? Then solve for the correct answer.

Answer 1

Answer:

He should spend 3 minutes or less on each scale

Sven made a mistake in the symbol of inequality, placing lesser or equal instead of greater or equal

Step-by-step explanation:

Let

t ------> is the number of minutes he spends on each scale

Remember that the phrase "at least"  is equal to "greater than or equal"

so

The inequality that represent this scenario is

$70-5t \geq 55$

solve for t

$-5t \geq 55-70$

$-5t \geq -15$

Multiply by -1 both sides

$5t \leq 15$

Divide by 5 both sides

$t \leq 3$

Sven is incorrect

He should spend 3 minutes or less on each scale

Sven made a mistake in the symbol of inequality, placing lesser or equal instead of greater or equal