Answer:
30 x 3 - 80 is 10
Step-by-step explanation:
(3x+1)+(4x-5)=8x-9
7x-1=8x-9
7x=8x-8
-x=-8
X=8
7
if : n = 2 : 15 - n = 15 - 8 = 7
-420