Answers:
8. 12x+3= 27
move 3 to the other side , sign changes from +3 to -3
12x+3-3=27-3
12x= 24
divide by 12 for both sides
12x/12=24/12
x= 2
9. 6(y-10)=42
mutiply the bracket by 6
(6)(y)(6)(-10)= 6y-60
6y-60= 42
move -60 to the other side, sign changes from -60 to +60
6y-60+60=42+60
6y=102
divide by 6
6y/6=102/6
y=17
10. 9x-2=4x+13
move +4x to the other side
9x-4x-2= 4x-4x+13
5x-2= 13
5x-2+2= 13+2
5x= 15
divide by 5 for both sides
5x/5= 15/5
x= 3
11. 4/3y+5/2y= 1
find the common denominator for both of the fractions which is 6.
Mutiply by 2 for 4/3y .
4(2)/3(2)y=8/6y
Mutiply by 3 for 5/2y
5(3)/2(3y)= 15/6y
8/6y+15/6y= 23/6y
23/6y= 1
Mutiply both sides by 6/23
23/6y(6/23)= 1 (6/23)
Cross out 6 and 6 , divide by 6 and then becomes 1.
Cross out 23 and 23, divide by 23 and then becomes 1.
1*1*y=y
y= 6/23