19y y 20 y 94x18 10x a b3a3b Solution2 9 4x 18 10x 9 18

19y -y = 20 y -9+4x+18= 10x a -b+3a-3b

2. -9 + 4x + 18 - 10x

(-9 +18) + ( 4x -10x ) = 9 -6x

3. a - b + 3a -3b

a +3a + -b -3b = 4a -4b

4. 2x^3 + 8x^2 - 13 - 4x^3 +1

= 2x^3 - 4x^3 +8x^2 -13 +1

= -2x^3 + 8x^2 -12

5. y/5 - y + 6y

= y( 1/5 -1 +6 )

= y( 1- 5 +6*5)/5 = y( 26)/5

= 26y/5

6. 3( x-2) + x+ 15

= 3x -6 +x +15

= 4x + 9

7. 5( 2z - 6) + ( 3 -z)

= 10z - 30 + 3 -z

= 9z - 27