Extra Math Practice #171-175

Which of the following equations, when plotted in the $xy$ -plane, will create a line that passes through the point $(2,5)$ and is parallel to the line formed by $3x-4y=12$ ?

A) $-6x+8y&=28$

B) $3x-4y=-12$

C) $-3x+4y=-14$

D) $-6x-8y&=-52$

In the equation below, the angle measures are in radians and $a$ is a constant.

$\begin{align*}\sin\left(\dfrac{\pi}{8}\right)=\cos\left(\dfrac{\pi}{a}\right)\end{align*}$

Which of the following could be the value of $a$ ?

A)8

B) $\dfrac{8}{3}$

C) $\dfrac{8}{7}$

D) $\dfrac{7}{8}$

$\begin{align*}3x+7y&=18\\2x-2y&=2\end{align*}$

Given the system of equations above, if $ax+ay=16$ , what is the value of $a$ ?

In the figure above, a circle with center $(-5, 2)$ passes through the point $(-1, 1)$ . Line $l$ , not shown, is tangent to the circle at $(-1, 1)$ . What is the $y$ -intercept of line $l$ ?

5 Last week, the share price of a certain stock increased by $1.33, or approximately 1.76 percent, from Monday morning when the stock market opened to Friday evening when the stock market closed. What was the share price of the stock on Friday evening after the market closed?

A)$75.57

B)$76.12

C)$76.90

D)$78.28