Answer:
x=1
Step-by-step explanation:
you would change it to 5x-4(-3x+5)=-3, because you put the info for the first equation into the second equation.
5x-4(-3x+5)=-3
5x+12x-20=-3
17x-20=-3
17x=17
x=1
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
Answer:
220
Step-by-step explanation:
110 cannot be the lcm for 20 but 10 and 110
so 220 can be the lcm for 20, 10, and 110
hope this helps
Answer: (-5, -3)
Step-by-step explanation:
(-10, -6)
-10/2 = -5
-6/2 = -3