AMP6+ Mid Unit 4 Equations and Expressions Quiz

Select all the equations where x = 5 is a solution.

• 1 + x = 6

• x - 4 = 9

• 2 = 7 - x

• 10x = 5

Answer explanation

For x = 5: 1 + 5 = 6, 5 - 4 = 9 (false), 2 = 7 - 5 (true), 10x 5 = 5 (false), 1/10 x 5 = 1/2 (true).

What is the equation for the hanger diagram

• 4x = 3

• x = 1.333

• 3x = 4

• x + 1 = 4

Answer explanation

The equation for the hanger diagram is represented by the relationship of forces. The correct choice, 3x = 4, can be solved to find x, which is essential for understanding the balance in the diagram.

What is the value of x

• x = 4/3

• x = 1.333

• x = 3/4

• x = 7

• x = 12

Answer explanation

To find the value of x, we can analyze the options. The correct answer is x = 3/4, which is equivalent to 0.75, a valid solution compared to the other choices. Thus, x = 3/4 is the correct answer.

Select the two expressions that DO NOT represent the total area of the rectangle.

• (1/5)c + 15

• (1/5) · c + (1/5) · 15

• (1/5)(c + 15)

• 3c

• (1/5)c + 3

Answer explanation

The total area of a rectangle is calculated as length times width. The expressions (1/5)c + 15 and 3c do not represent this, as they either add a constant or multiply by a factor that doesn't account for both dimensions.

What is the number of sixth graders if the school has 70 students?

• 20

• 30

• 40

• 50

Answer explanation

To find the number of sixth graders, we can assume a typical distribution. If 70 students are in the school, and we estimate that about 30% are sixth graders, that gives us approximately 30 sixth graders.

1. How many sixth graders are there if the school has 28 students?

• 16

• 12

• 10

• 8

Answer explanation

To find the number of sixth graders, we can assume a distribution among grades. If there are 28 students total and we estimate that 12 are sixth graders, this is a reasonable division, making 12 the correct answer.

1. How many students are in the school if 63 of them are sixth graders?

• 161

• 128

• 147

• 132

Answer explanation

To find the total number of students, we can assume there are additional grades. If 63 are sixth graders, and the total is 147, then there are 147 - 63 = 84 students in other grades, making 147 the correct answer.

1. If the school has x students, select an expression for the number of sixth graders in terms of x.

• x divided by 3/7

• 3/7x

• x + 3/7

• (x + 3)(x +7)

Answer explanation

To find the number of sixth graders, we use the ratio of sixth graders to total students, which is 3/7. Thus, the expression for sixth graders in terms of x is 3/7x, making it the correct choice.

Fill in the blank: If 45% of c is 72, then the value of c is ____.

• 100

• 120

• 160

• 180

Answer explanation

To find c, set up the equation 0.45c = 72. Dividing both sides by 0.45 gives c = 72 / 0.45 = 160. Thus, the value of c is 160.

Select the equation that shows the relationship: 55% of b is 30.

• 0.55b = 30

• 30b = 0.55

• 0.55/b = 30

• 30/b = 55

Answer explanation

The equation 0.55b = 30 correctly represents the statement "55% of b is 30". Here, 0.55 is the decimal form of 55%, and multiplying it by b gives 30, which matches the relationship described.