Question

Solve 12x = 4(x + 5)

Solve 15x - 3(3x + 4) =6
Solve 3x - 5x + 10 = 36
Solve 2(x+3)= x + 10

Answer 1

12x=4(x+5) (multiplying 4 by each argument in the parenhesis)
12x=4x+20 /-4x both sides
8x=20 /:8 divide both sides by 8

`x= (20)/(8)= 2 (4)/(8)=2.5`

15x-3(3x+4)=6 (-3 times each argument in the parenthesis)
15x-9x-12=6
6x-12=6 /+12 both sides
6x=18 /:6 divide both sides by 6
x=3

3x-5x+10=36
-2x+10=36 /-10 both sides
-2x=26 /:(-2) divide both sides by -2
x=-13

2(x+3)=x+10
2x+6=x+10 /-x
x+6=10 /-6
x=4