Answer:
Step-by-step explanation:
4x+2y = -24 -------------(i)
<u> -4x+y = 12 -</u>------------(ii)
add (i) &(ii) 3y = -12
y = -12/3
y = -4
Put y = (-4) in (i)
4x + 2*(-4) = -24
4x - 8 = -24
4x = -24 + 8
4x = -16
x = -16/4
x = -4
4/5 because look at the picture
<span>[ (1 / 36) - (1 / x²) ] / [ (1 / 6) + (1 / x) ]
[ (x² - 36) / 36x² ] / [ (x + 6) / 6x ]
</span>remember that<span>:
x² - 36 = (x + 6)(x - 6)
so
[ (x+6)(x-6) / 36x² ] / [ (x + 6) / 6x ]
[ (x+6)(x-6) / 36x² ] * [ 6x / (x + 6) ]
6x / 36x² = 1 / 6x
[ (x+6)(x-6) / 6x ] * [ 1 / (x+6) ] -------------------- > </span>(x - 6) / 6x<span>
The answer is </span>(x - 6) / 6x<span>
</span>
45% of 40 is 0.45×40=18 girls
if x girls join then 56% of 40+x is 0.56(40+x)=18+x
22.4+0.56x=18+x
put together like terms
4.4=0.44x
<span>x=10 girls joined</span>
Answer:
5 is the common ratio for your numbers
