7 + 2(x - 3) + 5x
= 7 + 2x - 6 + 5x <em>distributed 2 into x - 3</em>
= 7 - 6 + 2x + 5x <em>grouped like terms together</em>
= 1 + 7x
You didn't provide an image of the steps but hopefully you can figure it out based on the information I provided.
<span>Solve the system
9x = 27-9y
20x=71-9y
Let's use the "elimination through addition/subtraction method.
Multiply the first equation by -1 so as to obtain +9y:
-9x = -27 + 9y
</span><span>20x= 71- 9y
--------------------
Add these 2 equations together:
</span>-9x = -27 + 9y
20x= 71- 9y
--------------------
<span> 11x = 44
Solve this for x: x = 44/11 = 4.
Now find y by subst. 4 for x in either of the original equations.
Using the second equation: </span><span>
</span>20x=71-9y
20(4) = 71 - 9y
80-71 = -9y
9 = -9y. Then y = -1.
The solution set is (4,-1).
Part A: 7/10 because .7 represents 70/100 of a whole, or 7/10.
Part B: I think 1 and 89/100 because 89/100 represents that fraction
These are my answers, so I may be wrong.
Hope I helped, and good luck!
I'm guessing the sum is supposed to be
Split the summand into partial fractions:
If 
, then
If 
, then
This means
Consider the 
th partial sum of the series:
The sum telescopes so that
and as 
, the second term vanishes and leaves us with
