1 car - 4 wheels
1 motorcycle - 2 wheels
x - number of cars
y - number of motorcycles
so, there are 70 vehicles: x + y = 70
and all togeather they've got 258 wheels: 4*x + 2*y = 258
because each car has 4 wheels, so all car wheels = 4*x,
likewise 2*y for motorcycles
x + y = 70 /* 4
4 x + 2y = 258
4 x + 4 y = 280 (R1)
4 x + 2y = 258 (R2)
2y = 22 /:2 it is R1 - R2
x = 70 - y
y = 11 /motorcycles
x = 70 - 11 = 59 /cars
check:
59 + 11 = 70 ok
59 * 4 + 11 * 2 = 236 + 22 = 258 ok
Answer:
The atomic weight (or atomic mass) of Vanadium is 50.9415 which means that a "mole" of Vanadium atoms (6.02 x 10^23 atoms) will have a mass of 50.9415 grams. So, 214.1 grams of Vanadium would have
(214.1 / 50.9415) * (6.02 x 10^23) = 2.530 x 10^24 atoms
Step-by-step explanation:
Let’s give these two numbers variables
Let ‘a’ be the larger number
Let ‘b’ be the smaller number
Now from the question we know:
a + b = 30 or a = 30 - b
2a - 3b = 5
Now, let’s plug the first equation into the second to find ‘b’:
2(30 - b) - 3b = 5
60 - 2b - 3b = 5
60 - 5b = 5
55 = 5b
b = 11
Now we solve for ‘a’:
a = 30 - b
a = 30 - 11
a = 19
Now the question asks for the positive difference between the two numbers, so:
a - b = ?
19 - 11 = 8
Hope this helps!
