Answer:
one, no, one, infinitely
Step-by-step explanation:
a. you can get 7x = 21 - 21 = 0 ==> x = 0
b. subtract 12x from both sides ==> get 15 = -15, which is not true
c. -5x-5x=25+25 ==> -10x = 50 ==> x = -5
d. get -2x -6 -7 = -2x - 6 - 7 ==> so it's infinitely
Answer: Convex, heptagon, regular polygon
A
All you have to do is simplify all of them and put them in order from least to greatest.
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