Answer:
15. x = 4
16. a = 19
Step-by-step explanation:
"Cross multiply" essentially means "multiply both sides of the equation by the product of the denominators."
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<h3>15.</h3>
![\dfrac{x}{6}=\dfrac{2}{3}\\\\3(x)=6(2)\qquad\text{"cross multiply"}\\\\\boxed{x=4}\qquad\text{divide by 3}](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D%7B6%7D%3D%5Cdfrac%7B2%7D%7B3%7D%5C%5C%5C%5C3%28x%29%3D6%282%29%5Cqquad%5Ctext%7B%22cross%20multiply%22%7D%5C%5C%5C%5C%5Cboxed%7Bx%3D4%7D%5Cqquad%5Ctext%7Bdivide%20by%203%7D)
This is an example of a problem in which cross-multiplying introduces the need for an extra step: divide by 3. Had we simply multiplied by the denominator of the x-term, we would have been finished in one step:
x = 6(2/3) = 4
That is, rather than multiplying by the <em>product of the denominators</em>, sometimes the problem can be solved more easily if you multiply by their <em>least common multiple</em>.
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<h3>16.</h3>
![\dfrac{a+1}{a+5}=\dfrac{a-4}{a-1}\\\\(a-1)(a+1)=(a+5)(a-4)\qquad\text{"cross multiply"}\\\\a^2-1=a^2+a-20\qquad\text{simplify}\\\\\boxed{19=a}\qquad\text{add $20-a^2$}](https://tex.z-dn.net/?f=%5Cdfrac%7Ba%2B1%7D%7Ba%2B5%7D%3D%5Cdfrac%7Ba-4%7D%7Ba-1%7D%5C%5C%5C%5C%28a-1%29%28a%2B1%29%3D%28a%2B5%29%28a-4%29%5Cqquad%5Ctext%7B%22cross%20multiply%22%7D%5C%5C%5C%5Ca%5E2-1%3Da%5E2%2Ba-20%5Cqquad%5Ctext%7Bsimplify%7D%5C%5C%5C%5C%5Cboxed%7B19%3Da%7D%5Cqquad%5Ctext%7Badd%20%2420-a%5E2%24%7D)
1+2+3+... +n=
((1+n) x n) /2
is that the things you want
Answer:
A) x = y+25
B) 35 minutes
C) 35 ≠85
Step-by-step explanation:
A)
As we know
X = number of minutes Eric plays basketball
Y = Number of minutes he plays volleyball
x+y= 95
x = y+25
B)
We will replace
x=y+25 in the first equation and we will get (y+25) + y =95
On solving,
y+25+y =95
25+2y=95
2y=95-25
2y=70
y = 70/2
y = 35 minutes
C) X = 35
x+y= 95
35+y =95
y= 95-35
y = 60 minutes
Substituting value of Y as 60 , we get
x = y+25
35 = 60+25
35 ≠85
Answer:
30°=15° 52°=26° 172°=86° 171'30°=85.75°
Step-by-step explanation:
okay so re-reading over the question, and analyzing what the question wants us to answer, you will then realize that the way to get the answer is to divide x by 2.
our x examples, in this case, would be 30°,52°,172°, and 171'30°.
and that's how you find the answer to this type of question. :)))