Answer:
in the forth line of the equation it should be this
-6x+10=4x+20
-6x-4x=20-10
-10/-10x=10/-10
x=-1
Step-by-step explanation:
(21²+10²)½ = 23.25= 23.3
⇛6 + 3x = 7 - x
⇛3x + x = 7 - 6
⇛4x = 1
⇛x = 1/4
