Mohon Dijawab Pakai Cara , Jelas Dan baik... Mohon Yaa Bantuannya!!

1. a. 3m-2n+9m+15n-6
=3m+9m-2n+15n-6
= 12m + 13n-6
b. 9a²-3ab+4a+6ab+18a
= 9a²-3ab+6ab+4a+18a
= 9a²+3ab+22a
2. diket : x = 5, y = 2
a. 2x²-2y-5
= 2.5²-2.2-5
= 2.25 - 4-5
= 50-4-5
= 41
b. 5x+4y³-3
= 5.5 + 4.2³-3
= 25 + 4.8-3
= 25+32-3
= 57-3
=54
c. 3x²+2x-y+2
= 3.5²+2.5-2+2
= 3.25+10
=75+10
=85

semoga bermanfaat