Step-by-step explanation: the answer is 9h+40 because $9/hr rate is dependent on how many hours she worked (h), so it would be multiplied. She earned $40 already, so it would be added. the correct expression would be 9h + 40, or c.

4 0

3 years ago

Stoplight a changes color every 30 seconds and stoplight b changes every 40 seconds. after how many seconds will the stoplights

andrey2020 [161]

Answer:

After 120 seconds

Step-by-step explanation:

Here, we want to know the number of seconds after which both spotlights will change colors at the same time again.

Basically, what we want to do here is to

calculate the value with which 30 and 40 have the same multiples or we want to

calculate the lowest common multiple of 30 and 40

The multiples of 30 are 30,60,90,120 etc

The multiples of 40 are 40,80,120 etc

We can see that the lowest common multiple of both is 120

So therefore the spotlights will change colors at the same time after 120 seconds

6 0

2 years ago

Is △RWS ~ △QWT? yes no

Gekata [30.6K]

Yes
△RWS ~ △QWT

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5 0

2 years ago

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