Simple algebra, 2a-20 = -2 2a=18 a=18/2 a=9
-2a + 5 = 1 -2a = -5 + 1 -2a = -4 a = -4/-2 a = 2
2a + 10 + 5a - 2 = (2a + 5a) + (10 - 2) = 7a + 8
5a + 3 + (2a - 2) + a= 5a + 3 + 2a - 2 + a= 8a + 1
20 = 1Consider what is the value of 2a ÷ 2a? Any number divided by itself is 1. Thus:2a ÷ 2a = 1The law of indices says that when dividing, they are subtracted, for example:25 ÷ 22 = (2 x 2 x 2 x 2 x 2) ÷ (2 x 2) = 2 x 2 x 2 = 23 = 25-2So 2a ÷ 2a is (also):2a ÷ 2a = 2a-a = 20Since any number subtracted from itself is 0 (= a - a). This must have the same value as before, thus:20 = 1The 2 above can be replaced by any number x which means that any number to the power 0 is 1:x0 = 1
2a - 7 = -9 2a - 7 + 7 = -9 + 7 2a = -9 +7 2a = -2 2a/2 = -2/2 a = -2/2 a= -1
The answer is 4a^2.
2a + 2b = c subtract 2a from both sides 2a - 2a + 2b = c - 2a 2b = c - 2a divide both sides by 2 (2/2)b = (c - 2a)/2 b = (c - 2a)/2 --------------------
2a ÷a = 2
Simple algebra, 2a-20 = -2 2a=18 a=18/2 a=9
2a-4b = -2
-2a + 5 = 1 -2a = -5 + 1 -2a = -4 a = -4/-2 a = 2
1
2a+12=8 2a=-4 a=-2 So a is -2.
a/2a^2 You can take "a" out of both of those. It leaves you with 1/2a
2a + 10 + 5a - 2 = (2a + 5a) + (10 - 2) = 7a + 8
5a + 3 + (2a - 2) + a= 5a + 3 + 2a - 2 + a= 8a + 1