Answer:
12
Step-by-step explanation:
Ama's sister is 12 now and Ama is 8. 8/12 simplified is 2/3.
Four years ago Ama's would have been 4 and her sister would have been 8. 4/8 simplified is 1/2.
The equations:
(Ama is a)
(Ama's sister is s)
a = (2/3)s
a - 4 = (1/2)(s - 4)
Step one:
You would substitute the first equation into the second equation to get
(2/3)s - 4 = (1/2)(s - 4)
Step two:
Multiply by 6 to get rid of the fractions to get
4s - 24 = 3(s - 4)
Step three:
Simplify to get
4s - 24 = 3s - 12
Step four:
Subtract 3s and add 24 to get
s = 12
Step five:
Input the s value into the first equation to get
a = (2/3)(12) = 8
If this helped please rate, thanks, and mark brainliest! Also, please comment if it's correct :)
271,403.00000
Step-by-step explanation:
bearing in mind that, whenever we have an absolute value expression, is in effect a piece-wise function with a positive and a negative version of the expression, so
![\bf |x^2-4x-5|=7\implies \begin{cases} +(x^2-4x-5)=7\\\\ -(x^2-4x-5)=7 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ +(x^2-4x-5)=7\implies x^2-4x-5=7\implies x^2-4x-12=0 \\\\\\ (x-6)(x+2)=0\implies x= \begin{cases} 6\\ -2 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ -(x^2-4x-5)=7\implies x^2-4x-5=-7\implies x^2-4x+2=0 \\\\\\ (x-2)(x-2)=0\implies x = 2](https://tex.z-dn.net/?f=%5Cbf%20%7Cx%5E2-4x-5%7C%3D7%5Cimplies%20%5Cbegin%7Bcases%7D%20%2B%28x%5E2-4x-5%29%3D7%5C%5C%5C%5C%20-%28x%5E2-4x-5%29%3D7%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%2B%28x%5E2-4x-5%29%3D7%5Cimplies%20x%5E2-4x-5%3D7%5Cimplies%20x%5E2-4x-12%3D0%20%5C%5C%5C%5C%5C%5C%20%28x-6%29%28x%2B2%29%3D0%5Cimplies%20x%3D%20%5Cbegin%7Bcases%7D%206%5C%5C%20-2%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20-%28x%5E2-4x-5%29%3D7%5Cimplies%20x%5E2-4x-5%3D-7%5Cimplies%20x%5E2-4x%2B2%3D0%20%5C%5C%5C%5C%5C%5C%20%28x-2%29%28x-2%29%3D0%5Cimplies%20x%20%3D%202)