Answer:
c subtract 5 from both sides
It will be 3 hours until they are the same hight
Answer: 2d+3<=9
Step-by-step explanation:2 times a number is 2d plus 3 is +3 less than or equal to is <=
Ni : Zn: Cu = 7:2:9 =7x : 2x : 9x
7x+2x+9x = 3.8
18x=3.8
x=3.8/18=1.9/9≈0.21
Ni: 7x=7*0.21=1.47 ≈1.5 kg
Zn: 2x=2*0.21=0.42≈0.4 kg
Cu: 9x=9*0.21=1.89 ≈1.9 kg
Check 1.5+0.4+1.9 =3.8 True
