12s + 5 = 77
12s = 77 - 5 = 72
s = 72/12
s = 6 ...//
Ans = C ... 12x + 5 = 77 ...
Answer:
139
Step-by-step explanation:
Substitute x for 15.
9(15)+4
Then multiply:
135+4
And then add:
139
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:
see explanation
Step-by-step explanation:
To prove that BC ≅ AD, that is that BC = AD
You would need to prove the lengths are the same.
