找到你今天要练的题。

What is the x-intercept of the graph of \( y=\frac{21-x}{ax+b} \) in the xy-plane, where a and b are positive constants?

What is the x-intercept of the graph of \( y=\frac{28-x}{ax+b} \) in the xy-plane, where a and b are positive constants?

\( \frac{z+4}{5r^2}-\frac{5}{z+4}=0 \) 
In the given equation, r is a positive constant. A solution to this equation is \( −84 \). What is the value of r?

In the xy-plane, the graph of function \( f \), where \( y=f\left(x\right) \), has exactly \( 8 \) x-intercepts. One of these x-intercepts is \( \left(17,\ 0\right) \). The rational function g is defined by \( g\left(x\right)=\frac{f\left(x\right)}{x-17} \). In the xy-plane, how many x-intercepts does the graph of \( y=g\left(x\right) \) have?

The function \( j \)  is defined by \( j(x)=\frac{4x+2}{9p} \), and the function \( k \) is defined by \( k(x)=\frac{j(x)·p}{x+1} \), where \( p \) is a positive constant. What is the value of \( k(3) \)?

If \( \frac{48}{x}=4x \), what is the value of \( 4x^2 \)?

\( g(x)=\frac{x^2-x-a}{x^2-x-b} \) 
The function g is defined by the given equation, where a and b are constants. In the xy-plane, the graph of \( y=g(x) \) passes through the point (0, 43), and \( g(-43)=0 \) . What is the value of b?

Which expression is equivalent to \( \frac{3x(x-8)-9(x-8)}{2x-16} \), where \( x>8 \)?

Which expression is equivalent to \( \frac{y+12}{x-8}+\frac{y\left(x-8\right)}{x^2y-8xy} \) ?

\( g(x)=\frac{x^2-x-a}{x^3-x-b} \) 
The function g is defined by the given equation, where a and b are constants. In the xy-plane, the graph of \( y=g(x) \) passes through the point (0, 22), and \( g(-22)=0 \). What is the value of b?

Which expression is equivalent to \( \frac{42a}{k}+42ak \) , where \( k \)>0?

The function \( h \) is defined by\( h\left(x\right)=\frac{8}{5x+6} \). What is the value of \( h\left(2\right) \)?