(C) If \( a, b, c \) and \( d \) are proportion quantities, then prove that: \( \frac{a+2 c}{b+2 d}=\frac{c-a}{d-b} \) (a) If \( \frac{a}{x+y}=\frac{b}{y-2 x}=\frac{c}{x+4 y} \), find the value of : \( \frac{b+2 c}{2 a+b} \) (b) If \( y=3+a \) and \( a \propto \frac{1}{x} \) and \( y=5 \) when \( x=1 \), find the relation bet \( x \) and \( y \), then find the value of \( y \) when \( x=2 \)

The cost price of a pen is Rs \( (3 x+5) \) and is selling price is \( \operatorname{Rs}(4 x+3) \) Write the formulato find protit.

O Functions and Lines Evaluating functions: Linear and quadratic or cubic The functions \( f \) and \( g \) are defined as follows. \[ f(x)=-2 x^{2}-3 \quad g(x)=3 x-1 \] Find \( f(5) \) and \( g(-2) \). Simplify your answers as much as possible. \[ f(5)=\square \] \( g(-2)=\square \)

зАданив №2 Дополните выражение до полного квадрата разности и запишите получившийся квадрат разности: \( \quad l^{2}-14 l+()^{2}=( \)

\( 8 x y \) is a monomial expression. Is the statement true or fause?

Evaluating functions: Linear and quadratic or cubic The functions \( f \) and \( g \) are defined as follows. \( f(x)=3 x^{3}+5 \quad g(x)=-5 x+4 \) Find \( f(-2) \) and \( g(7) \). \[ f(-2)=\square \] \( g(7)=\square \)