With mental math, you can perform equations quickly and efficiently. They also help you to develop your own strategies and solve more complex math equations. Hope this helps;)
Answer:
Step-by-step explanation:
Question: 5 - 7(z+1) = 7(-9-3z)
We multiply the number in front of the bracket first, since that is multiplication.
--> 5 -7z -7 = -63 - 21z
--> -7z -2 = -63 - 21z
Now, we move all the z and all the numbers to each side.
--> -7z +21z = -63 +2
--> 14z = -61
--> z = -61/14
This cannot be simplified further, so z is -61/14.
Marcus would need to save for 24 weeks in order to purchase a new electronic keyboard.
<h3>Define the meaning of the equation?</h3>
A mathematical assertion in which you use mathematical symbols to demonstrate that two sums are equal.
As per specified data-
- Marcus wishes to save $378 so that he can purchase a new electronic keyboard.
- Every week, he saves $15.75 from his paycheck.
Let 'x' be the number of weeks required to complete the amount.
The equation becomes.
378 = 15.75x
For the number of week required.
x = 378/15.75
x = 24
Thus, Marcus would need to save for 24 weeks in order to purchase a new electronic keyboard.
To know more about the equation, here
brainly.com/question/14107099
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