13. Which is the correct solution to the equation shown? \[ 0.4(5 x-12)+0.5 x=15.2 \] A. \( x=8 \) B. \( x=-8 \) C. \( x=17.5 \) D. \( x=4.16 \)

15 It is given that \( t=\frac{b^{2}-4}{3-b^{2}} \). Express \( b \) in terms of \( t \)

Câu 03: (a) Rût gơn biểu thực \[ \left(\frac{1-x}{x^{2}+x^{3}-x^{4}}-\frac{x^{2}+x+2}{x^{5}-x^{3}-2 x^{2}-x}\right):\left(\frac{1+x^{4}}{x^{3}+x^{4}+x^{5}}-\frac{1-x+x^{2}}{x}\right) \] (b) Phân tích phân thức \( \frac{1}{(x-1)(x-2)(x-3)(x-4)} \) thành tổng các phân thức dơn giản.

QUESTION 12 If \( 2^{x} 5^{y}=16 \times 125 \), where \( x \) and \( y \) are positive integers, determine \( x-y \) :

\( f(x)=5 x+6 ; g(x)=3 x-2 \) (h) Find \( \left(\frac{1}{g}\right)(1) \).

\( x^{2}-(k+3) x-7=0 \) seja igual a 8