-2(10r + 4) + 10(7r + 2)
Mathematics · Middle School · Tue Nov 03 2020
Answered on
Lets try and remove the brackets by multiplying the numbers with their brackets.
-2(10r+4)=-20r-8
10(7r+2)=70r+20
So we will have now:
-20r-8=70r+20
Lets put the variables on one side and the numbers on the other side. Every variable or number that will change signs, will have their sign changed from a + into a - and vice versa.
70r+20r=-8-20
90r = -28
Divide both sides with 90.
90r/90 = -28/90
r=-28/90