Answer:
The first answer is correct.
Step-by-step explanation:
Line 5 says that the reason is due to substitution
Line 3 says m∠ SQT equals 180°
If we substitute 180° into the spot for m∠ SQT in line 4, we get solution option 1
Answer:social and economic changes that mark the transition from a stable agricultural and commercial society to a modern industrial society relying on complex machinery rather than tools.
Step-by-step explanation:
There are 6C3 = 20 such combinations.
abc, abd, abe, abf
acd, ace, acf, ade
adf, aef, bcd, bce
bcf, bde, bdf, bef
cde, cdf, cef, def