x² -10x + y² + 6y = 2
The graph in the xy-plane of the equation above is a circle. What are the coordinates of the center of the circle?

If x > 0, which of the following is equivalent  to 

From 1990 to 2001, German currency included coins called pfennigs, worth 1 pfennig each, and groschen, worth 10 pfennigs each. Which equation represents the number of pfennig coins, p, and groschen coins, g, that have a combined value of 85 pfennigs?

Isolating a variable entails rearranging an algebraic equation so that one variable stands alone. A goal is to select a set of operations that will leave the variable of interest on one side of the equal sign while putting all other terms on the other.
¶To isolate a quantity in a formula or equation:
1. Make a note of the original equation. If necessary, convert the word problem or context into an equation.
2. Begin isolating the desired quantity by performing the operation on both sides of the equation.
3. Repeat Step 2 until you have isolated the desired quantity.

A line in the xy-plane has a slope of 1 and passes through the point (0, 2). Which is an equation of the line?

x + 7 = 3(x - 3)
What value of x satisfies the given equation?

x² + 10 = 91
What is the positive solution to the given equation?

In the xy-plane, line k with equation y = mx + b, where m and b are constants, passes through the point (-3, I). If line k is perpendicular to the line with equation y = - 2x + 3, what is the value of b ?

Questions 55 and 56 refer to the following information.
As of 2016, there were 118 known elements. These elements can be described with 10 classifications as summarized in the given table.

The percentage of the 10 classifications that have 11 or more elements is p%. What is the value of p ?

The expression 3xy(2 y + 3) is equivalent to bxy² + 9xy, where b is a constant. What is the value of b?

5x + 3y = 31
5x - 4y = 17
If (x, y) is the solution to the given system of equations, what is the value of 10x - y ?

One of the two equations in a linear system is given. The system has no solution. Which equation could be the second equation in this system?

Data set R and data set S are represented in the dot plots shown. The mean for each data set is 50.0. Which of the following best describes the relationship between the standard deviation of data set R and the standard deviation of data set S?

The graph of the line  in the xy-plane is  translated 2 units to the right. What is the y-intercept of the translated line?

For a certain type of aircraft, the ratio of thrust, in newtons, to weight, in newtons, is 27 to 100. If an aircraft has a weight of 3,730,000 newtons, which of the following is closest to the thrust, in newtons, of the aircraft?

|x + 3| = 0
Exactly how many solutions does the given equation have?

Crawford County, Iowa, is shaped like a rectangle. The length of the county is 6 miles longer than the width of the county. If A(x) is the area of the county, in square miles, and x is the width, in miles, which equation best models the area of the county?