A number subtracted from 90 is 3 times that number

Mathematics

2 answers:

OleMash [197]3 years ago

7 0

90-n=3n hope this helps you

Harlamova29_29 [7]3 years ago

3 0

The equation is 90-n=3n but then to solve it you add n to both sides to get the variable on one side so then
90-n=3n becomes 90=4n and n=22.5
so the number is 22.5

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What process do you use to find the percent change of a quantity?

Sever21 [200]

First, we need to get the amount of change:
The amount of change can either be an increase or a decrease.
It can be calculated as follows:
amount of change = $\frac{"new"value - "old"value}{"old" value}$

If the amount of change is positive, then it is an increase
If the amount of change is negative, then it is a decrease

Then, we need to convert this amount into a percentage:
Changing the amount into a percentage can simply be done by multiplying this amount by 100
This means that:
% of change = amount of change * 100

Combining the two steps:
% of change = $\frac{"new"value - "old"value}{"old" value}$ * 100

Examples:
The original price of a certain product was $10. It then became $12. Find the % of increase.
% of change = $\frac{12-10}{10} * 100$ = 20%
This means that the price increased by 20%

The temperature decreased from 25 degrees to 20 degrees. Find the percentage of decrease.
% of decrease = $\frac{20-25}{25} * 100$ = -20%
This means that the temperature decreased by 20%

Hope this helps :)

7 0

3 years ago

Read 2 more answers

Help meeeeeeeeeeee with all of these questions

kaheart [24]

Answer:
1. Step 2: 2a-6+6 Step 3: 2a
2. Step 2: 8(2d+3)

Step by step explanation:
Here’s my work form what I seen: