Answer:110
Step-by-step explanation:x^2+17x=15x+35
x^2+17x-15x-35=0
x^2+2x-35=0
delta=2^2-4*1*(-35)=4+140=144
x1=(-2+V144)/2=(-2+12)/2=10/2
x=5
so 15*5+35=75+35=110
20 and 10, 20 is 2 times 10 and if you add them together its 30
3w-7w-12=2w-6
-4w-12=2w-6
-12=6w-6
-6=6w
w=-1