4. Число -6 является корнем уравнения \( 2 x^{2}+b x-6=0 \). Найдите второй корень уравнения и значение \( b \). 5. При каком значении \( a \) уравнение \( 2 x^{2}+4 x+a=0 \) имеет единственный корень?

7. \( \begin{aligned} y & =2 x+8 \\ y & =-2 x\end{aligned} \)

Given \( f(x)=-3 x+4 \) and \( g(x)=x+7 \), what is the value of \( g(f(2)) ? \)

5. Fourth term of arith sequence is 11 , and the \( 6^{2} \) term is 17 . Find the second term. \( a_{4}=11 \quad a_{6}=17 \quad a_{1}+(n-1) \)

Determine whether the following equation defines \( y \) as a function of \( x \). \[ x^{2}+y=49 \] Does the equation \( x^{2}+y=49 \) define \( y \) as a function of \( x \) ? Yes No

Let \( A=\left[\begin{array}{cc}4 & 5 \\ 1 & -5\end{array}\right] \) and \( B=\left[\begin{array}{cc}2 & -6 \\ 2 & 3\end{array}\right] \) Find \( -2 A+5 B \) \( -2 A+5 B= \)