3.2.2 Algebraic Expressions II, PT3 Focus Practice


Question 6:
Simplify 4( 5x3 )+7x1.

Solution:
4( 5x3 )+7x1 =20x+12+7x1 =13x+11

Question 7:
( 3x2y )( x+4y )

Solution:
( 3x2y )( x+4y ) =3x2yx4y =2x6y

Question 8:
Simplify 3( 2a4b ) 1 3 ( 6a15b )

Solution:
3( 2a4b ) 1 3 ( 6a15b ) =6a+12b2a+5b =8a+17b

Question 9:
1 3 ( 2x+6y9z ) 1 6 ( 4x18y+24z )

Solution:
1 3 ( 2x+6y9z ) 1 6 ( 4x18y+24z ) = 2 3 x +2y3z + 2 3 x +3y4z =5y7z

Question 10:
1 2 ( a+6bc ) 1 5 ( 3+2bc2a )

Solution:
1 2 ( a+6bc ) 1 5 ( 3+2bc2a ) = 1 2 a+3bc 3 5 2 5 bc+ 2 5 a = 5a+4a 10 + 15bc2bc 5 3 5 = 9a 10 + 13bc 5 3 5