1) 12a + 6.4 - 5 - 2a - 3a + 3.6= 12a + 6.4 - 5 - 2a - 3a + 3.6= 12a - 5a + 3.6 + 6.4 - 5 + 3.6= 4a + 7.6
2) -9 + 1.5x + 2x + 6 + 4.5x - 0.9= -9 + 1.5x + 2x + 6 + 4.5x - 0.9= 1.5x + 2x + 4.5x - 9 + 6 - 0.9= 8.0x - 3.9
3) 1.6y - 2.4 + 8 - 2y + 5.6 - 2(0.8y) + 3.4= 1.6y - 2.4 + 8 - 2y + 5.6 - 1.6y + 3.4= 1.6y - 2y - 1.6y - 2.4 + 8 + 5.6 + 3.4= -2.4 + 8 + 5.6 + 3.4= 15.6
4) 5/6n + 5*6 - 2/3(9) + 1/3n + 5/8= 5/6n + 30 - 6 + 1/3n + 5/8= 5/6n + 24 + 1/3n + 5/8
1) 12a + 6.4 - 5 - 2a - 3a + 3.6
= 12a + 6.4 - 5 - 2a - 3a + 3.6
= 12a - 5a + 3.6 + 6.4 - 5 + 3.6
= 4a + 7.6
2) -9 + 1.5x + 2x + 6 + 4.5x - 0.9
= -9 + 1.5x + 2x + 6 + 4.5x - 0.9
= 1.5x + 2x + 4.5x - 9 + 6 - 0.9
= 8.0x - 3.9
3) 1.6y - 2.4 + 8 - 2y + 5.6 - 2(0.8y) + 3.4
= 1.6y - 2.4 + 8 - 2y + 5.6 - 1.6y + 3.4
= 1.6y - 2y - 1.6y - 2.4 + 8 + 5.6 + 3.4
= -2.4 + 8 + 5.6 + 3.4
= 15.6
4) 5/6n + 5*6 - 2/3(9) + 1/3n + 5/8
= 5/6n + 30 - 6 + 1/3n + 5/8
= 5/6n + 24 + 1/3n + 5/8