Answer:
1.22 x 
Step-by-step explanation:
1,220,000 would be...
1.22 x 10^6
Answer:
First mechanic worked for 10 hours and second mechanic worked for 15 hours.
Step-by-step explanation:
Let first mechanic worked for X hours and second mechanic worked for Y hours .
Now, according to the question , they worked for a total of 25 hours .
Thus ,
X + Y = 25.
Y = 25 - X -(1)
Also, first mechanic is charging $ 95 per hour and second mechanic is charging $115 per hour .
Thus, total money charged by them will be 95X + 115Y .
Which is given to be $2675 in the question.
Thus 95X + 115Y = 2675. -(2)
Putting equation 1 in equation 2 we get ,
95X + 2875 - 115X = 2675
20X = 200
X = 10 hours.
Thus , Y = 25 - X = 15 hours.
Thus first mechanic worked for 10 hours and second mechanic worked for 15 hours.
Using a system of equations, it is found that David is 12 years old.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
The variables are given as follows:
- Variable z: Rebecca's age.
David is three times younger than the dad and twice as old as Rebecca, then:
Rebecca is 30 years younger than the dad, hence:
z = y - 30.
Then, since x = 2z and z = y - 30 and y = 3x, we solve for x to find David's age.
x = 2(y - 30)
x = 2(3x - 30)
x = 6x - 60
5x = 60
x = 60/5
x = 12.
David is 12 years old.
More can be learned about a system of equations at brainly.com/question/24342899
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Get like terms together. you might have to move across the equals sign
3x-x=-6+82
2x=76
x=38
