3. 10a+2a+4a
13b- 5b +b
2c- 6c + 5c
4. 2x + 2 *3x + 2* x + 3x + 4x= 17x
2* 2a+ 2* a + 2* 3a-5= 4a+2a+6a- 10= 12a-5
4t+2 +t-1+t+3+t= 7t+4
5. 3x*3 =45x:5
-2x*(-10)= - 20x
2x*8=16x
-x*(-5)= 5x
-4*5x=60x/3
4*3x= 6*2x
