3x-5y-6x-7y + 9x-2y, can you help me solve this problem of merging similar terms and teach me how to solve it

3x-5y-6x-7y + 9x-2y, can you help me solve this problem of merging similar terms and teach me how to solve it

3x-5y-6x-7y+9x-2y
=(3-6+9)x+(-5-7-2)y
=6x-14y