Again, to fly through the afternoon, I've given the team some more maths to keep their brains bubbling!
Could someone please provide for the answers and working for the following:
A)
$\displaystyle \begin{aligned}
x(x + 4) &= 21 \\
x^2 + 4x &= 21 \\
x^2 + 4x - 21 &= 0 \\
(x + 7)(x - 3) &= 0 \\
x + 7 &= 0\;\;\Rightarrow\;\; x = -7 \\
x - 3 &= 0\;\;\Rightarrow\;\; x = 3
\end{aligned}$
B)
$\displaystyle \begin{aligned}
\frac{x - 1}{3} - \frac{x - 1}{2} &= 6 \\
6\left(\frac{x - 1}{3} - \frac{x - 1}{2}\right) &= 6(6) \\
2(x - 1) - 3(x - 1) &= 36 \\
2x - 2 - 3x + 3 &= 36 \\
-x + 1 &= 36 \\
-x &= 35 \\
x &= -35
\end{aligned}$
01
$\displaystyle (a)\;9xy+8y-4y^2 +9y-2x^2y=9xy+17y-4y^2 -2x^2 y$
$\displaystyle (b)\;(3x^2)^4=3^4\times (x^2)^4=81x^8$
$\displaystyle (c)\;\frac{24x^6 y^2}{6x^2 y}=\frac{4x^6y^2}{x^2 y}=4x^4 y$
$\displaystyle (d)\;\frac{8x-6(2x+4)+10)}{8}=\frac{8x-12x-24+10}{8}$ $\displaystyle \;=\frac{-4x-14}{8}=\frac{-2(2x+7)}{8}=-\frac{2x+7}{4}$