91Ó°ÊÓ

Find the slope of the line that passes through the given points. $$(-3,4),(-7,-4)$$

Solve the given systems of equations by the method of elimination by substitution. $$\begin{aligned} &3 x+y=1\\\ &2 y=3 x-16 \end{aligned}$$

For each given value of \(x,\) determine the value of y that gives a solution to the given linear equations in two unknowns. $$6 y-5 x=60 ; \quad x=-10, x=8$$

Solve each system of equations by sketching the graphs. Use the slope and the \(y\) -intercept or both intercepts. Estimate each result to the nearest 0,1 if necessary. $$\begin{aligned} &-5 x+3 y=15\\\ &2 x+7 y=14 \end{aligned}$$

Evaluate the given determinants. $$\left|\begin{array}{rr} -20 & -15 \\ -8 & -6 \end{array}\right|$$

Evaluate the given determinants. $$\left|\begin{array}{cc} -20 & -15 \\ -8 & -6 \end{array}\right|$$

Solve the given systems of equations. $$\begin{aligned}&2 u+2 v+3 w=0\\\&3 u+v+4 w=21\\\&-u-3 v+7 w=15\end{aligned}$$

Solve each system of equations by sketching the graphs. Use the slope and the \(y\) -intercept or both intercepts. Estimate each result to the nearest 0,1 if necessary. $$\begin{aligned} &s-4 t=8\\\ &2 s=t+4 \end{aligned}$$

Find the slope of the line that passes through the given points. $$(0.4,0.5),(-0.2,0.2)$$

Evaluate the given third-order determinants. $$\left|\begin{array}{rrr} 25 & 18 & -50 \\ -30 & 40 & -12 \\ -20 & 55 & -22 \end{array}\right|$$