Its step 2 my guy.....................................
Answer:
There are a lot of turning point in the history of algebra one of those is the discovery of the plain and the quadrants by Rene Descartes. This discovery paved way to a lot of knowledge which was later on use in solving other complicated mathematical problems.
Step-by-step explanation:
50 + 3x = 7x + 12
This is because of the exterior angle theorem.
Answer:
-4x + 12 = 20 is incorrect. she added 12 to 20 instead of subtracting 12 from both sides.
Step-by-step explanation:
It should have been, write problem
-4(x - 3) = 20
Use distributive property.
-4x + 12 = 20
subtract 12 from each side
-4x =8
divide each side by -4
x = -2