The system of equations is:
x = 2y
x*$10 + y*8 = $84
Solving it, we see that he worked 3 hours landscaping and 6 hours washing cars.
<h3>
How to write the system of equations?</h3>
First, we need to define the variables:
- x = number of hours washing cars.
- y = number of hours landscaping.
We know that Alexander worked twice as many hours washing cars as he worked hours landscaping, then:
x = 2y
We also know that he earned a total of $84, then:
x*$10 + y*8 = $84
So the system of equations is:
x = 2y
x*$10 + y*8 = $84
To solve it, we just replace the first equation into the second one:
(2y)*$10 + y*8 = $84
y*$28 = $84
y = $84/$28 = 3
So He worked 3 hours landscaping, and:
x = 2*y = 2*3 = 6
6 hours washing cars.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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Answer:
i need more information to answer this
Step-by-step explanation:
Divide by the coefficient of e^2, then take the square root.
e^2 = 49/(9f)
e = ±7/(3√f) = ±(7√f)/(3f)
The 3rd selection is appropriate:
e=±(7√f)/(3f)
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When written in plain text (not typeset), any denominator containing arithmetic must be enclosed in parentheses. When the expression is typeset, the surd and the division bar do the grouping for you.