How do you simplify #(4y-9)-(3y+10)#?

1 Answer
Apr 16, 2016

Answer:

#y - 19#

Explanation:

A place where students commonly make mistakes with is the terms after the subtraction sign, in this case #3y + 10#.

Pretend that there is a negative 1 in front of #(3y + 10)#. So you would have: #-1(3y + 10)#

Distribute that negative one to the terms in the parenthesis, to get #-1(3y) + -1(10) = -3y - 10#

Combine that with the remaining expression and then simplify.
#4y - 9 - 3y - 10#

Combine like terms:
#(4y - 3y) = y#
#(-9 - 10) = -19#

Put those together to get the answer of:
#y - 19#