The GCF is 5a.
Oh, dude, 5a x 5a is just 25a^2. It's like multiplying 5 by 5 to get 25, and then you just stick that 'a' in there twice because math said so. So yeah, 25a^2, easy peasy lemon squeezy.
5a = a + a + a + a + a
5a = -5a + 5Add 5a to each side:10a = 5Divide each side by 10:a = 5/10 = 1/2
(5a)^2 or a^2+10a+25
5a or 4a squared
30-5a = 25
It is: 5a2
6b-5a = 1
2a - 5a = -3a
5a-20 = -15
5a- 2a = 3