Answer:
7 boxes of pencils and 5 boxes of erasers.
Step-by-step explanation:
The least common denominator of these two numbers are 70. 7×10 and 14×5. So she is purchasing the same quantity of both.
-9 i believe because 9x3=27
First you had to add by twenty-two from both sides of equation form.

Then simplify by equation.

Next, you divide by four from both sides of equation form.

Finally, simplify by equation.





Final answer: 
Hope this helps!
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-Charlie