Solving for Unknowns

What is the value of x in the equation 9.3 + x = 42.8?

• 33.5

• 34.5

• 35.5

• 36.5

Fill in the blank: In the equation X - 72 = 239, the value of X is ____.

• A) 311

• B) 312

• C) 313

• D) 314

Tags

TEKS.MATH.6.10A

What is the value of x in the equation 1.2x = 27.6?

• 22

• 23

• 24

• 25

• -52

• -53

• -54

• -55

Solve the following system of equations using the elimination method: 2x + 3y = 11 and 4x - 2y = 6

• x = 2.5, y = 2

• x = 2, y = 2.5

• x = 5, y = 2

• x = 2, y = 4

Answer explanation

To solve the system of equations, multiply the first equation by 2 to eliminate y. Then subtract the second equation from the first to find x. Substitute x back to find y. The correct solution is x = 2.5, y = 2.

Using the elimination method, solve the system of equations: 3x - 2y = 16 and 2x + 2y = 4

• The solution is x = 4 and y = -2.

• The solution is x = 0 and y = 0.

• The solution is x = -3 and y = 5.

• The solution is x = 2 and y = 3.

Answer explanation

By adding the two equations, we eliminate y, giving 5x = 20. Solving for x, we get x = 4. Substituting x back into one of the equations, we find y = -2. Therefore, the solution is x = 4 and y = -2.

Solve the following system of equations using the elimination method: 5x + 2y = 23 and 3x - 4y = -7

• x = 3, y = 4

• x = 4, y = 5

• x = 2, y = 3

• x = 5, y = 2

Answer explanation

To solve the system of equations, multiply the first equation by 2 and the second equation by 5 to eliminate y. Then, subtract the equations to find x = 3. Substitute x back to find y = 4. Therefore, x = 3 and y = 4.

Solve the following system of equations using the elimination method: 3x - y = 5 and 2x + y = 7

• x = 6, y = 2

• x = 2, y = 3

• x = 5, y = 1

• x = 4, y = -1

Answer explanation

To solve the system of equations, add the two equations together to eliminate y. This gives 5x = 12, so x = 4. Substitute x back into one of the equations to find y, giving y = -1. Therefore, x = 4 and y = -1.

What is the first step in using the elimination method to solve simultaneous equations?

• Subtract one equation from the other

• Add the two equations together

• Divide both equations by a common factor

• Make the coefficients of one of the variables the same in both equations

Answer explanation

The first step in using the elimination method is to make the coefficients of one of the variables the same in both equations.

In the equation 5x - 4y = 20, what is the coefficient of y?

• 5

• -4

• 4

• 20

Answer explanation

The coefficient of y in the equation 5x - 4y = 20 is -4 because it is the number directly multiplied by y.