show 5x-15 is proportional to 6-2x

5x - 15 = 6 - 2x 

x ( 2 + 5) = 21

x = 21 / 7 = 3

so when x = 3

grts Diek

5x - 15  :   6 - 2x        rewrite the right side

5x - 15  :  -2x + 6        factor

5(x - 3)  :  -2 ( x - 3)     divide by (x - 3)

5 :  - 2