Collect like terms? Math help?

11a + 6c + 4a


And also for 3r + 2r^2 + 4r

like terms are either numbers or terms having the same variable........

11a + 6c + 4a = 15a + 6c

3r + 2r^2 + 4r = 2r^2 + 7r

if the letter (the variable) beside the number is the same than you can add the numbers together and put the same letter (variable) after it

11a+4a=16a
=15a +6c

3r+2r+4r
=9r ^2

15a+6c