The <em><u>correct answer</u></em> is:
15 bicycles and 6 skateboards.
Explanation:
Let x represent the number of bicycles and y represent the number of skateboards. The first equation in our system is then
x+y = 21, since there are 21 total items in the shop.
Each bicycle has 2 tires and each skateboard has 4; this gives us the equation
2x+4y=54 (because they are ordering 54 tires).
This makes our system
We will use elimination to solve this; we first need one of the variables to have the same coefficient in both equations. We will make x the same, and we will do this by multiplying the first equation by 2:
Now we will subtract the second equation from the first one:
Divide both sides by -2:
-2y/-2 = -12/-2
y = 6
There were 6 skateboards. Substituting this into the first equation,
x+6 = 21
Subtract 6 from each side:
x+6-6 = 21-6
x = 15
There were 15 bicycles.
Answer:
<em> 1,407</em>
<em>x 14</em>
<em>_______</em>
<em> 5,628</em>
<em>+ 1,4070</em>
<em>______</em>
19,698
<em>The two partial products are 5,628 and 14,070</em>
<span>4x + 8 = −2 − 2 + 5x
5x - 4x = 8 + 4
x = 12
There's only one solution, x = 12</span>
X=7
Explanation:
A triangle equals 180°, and they gave us one length already, and it says the one arm of the triangle is equal to the other so we know that the third angle is going to be the same as the second angle.
180=90+(6x+3)+(6x+3)
Combine like terms
180=96+12x
Subtract 96 from both sides
84=12x
Divide 12 by both sides
7=x
Now check it,
90+(6*7+3)+(6*7+3)
90+(45)+(45) =180
1. a b c
2. a b c
3. a b c
4. a b c
5. a b c
then she eliminated 1 choice in 1 and 2, say as follows
1. b c
2. a b
3. a b c
4. a b c
5. a b c
Probability of answering correctly the first 2, and at least 2 or the remaining 3 is
P(answering 1,2 and exactly 2 of 3.4.or 5.)+P(answering 1,2 and also 3,4,5 )
P(answering 1,2 and exactly 2 of 3.4.or 5.)=
P(1,2,3,4 correct, 5 wrong)+P(1,2,3,5 correct, 4 wrong)+P(1,2,4,5 correct, 3 wrong)
also P(1,2,3,4 c, 5w)=P(1,2,3,5 c 4w)=P(1,2,4,5 c 3w )
so
P(answering 1,2 and exactly 2 of 3.4.or 5.)=3*P(1,2,3,4)=3*1/2*1/2*1/3*1/3*2/3=1/4*2/9=2/36=1/18
note: P(1 correct)=1/2
P(2 correct)=1/2
P(3 correct)=1/3
P(4 correct)=1/3
P(5 wrong) = 2/3
P(answering 1,2 and also 3,4,5 )=1/2*1/2*1/3*1/3*1/3=1/108
Ans: P= 1/18+1/108=(6+1)/108=7/108
