How do you solve #3a + 12+ ( - 3a ) = 5a + 7+ ( - 3a )#?

1 Answer
Apr 15, 2018

#color(brown)(a = 5/2#

Explanation:

http://maths.nayland.school.nz/Year_11/AS1.1_Number/1_bedmas.htm

Carryout the operations as per the order above while solving an equation.

#3a + 12 + (-3a) = 5a + 7 + (-3a)#

#3a + 12 - 3a = 5a + 7 - 3a, " removing brackets"#

#3a - 3a + 12 = 5a - 3a + 7, " rearranging like terms together"#

#cancel(3a) - cancel(3a) + 12 = cancel(5a-3a)^color(red)(2a) + 7#

#12 = 2a + 7#

#2a = 12 - 7, " separating constants and variables"#

#2a = 5 " or " a = 5/2#