Mod 5 Unit Test Review Grade 7

Equivalent Expressions

100

Simplify:  7x² + 12x - 18x²

ANSWER:  -11x² + 12x

7x²-18x²+12x      commutative property

   -11x² + 12x     combine like terms

200

Fill in the blank:

-10x + 4 +5x = 4 + _

Answer -5x

-10x + 4 +5x

-10x + 5x + 4

-5x + 4

300

Simplify:

3/4n + 3m - 1/3n + 1/4n

Answer: 

5/12n + 3 1/4m

3/4n + 3m - 1/3n + 1/4n

5/12n + 3 1/4 m

3/4n + 3m - 1/3n + 1/4m

3/4n -1/3n +3m + 1/4m

5/12n + 3 1/4m

400

What is the perimeter of a triangle with sides of (3x+4), (9x-5) and (7x+5)?

ANSWER: (19x + 4) units

perimeter is the sum of all sides of a shape

P = (3x+4) + (9x-5) + (7x+5)

P = 3x+9x+7x+4-5+5    commutative property

P = (19x + 4) units      combine like terms

500

Simpify:  (3/4 x +7) - (x-10)

Answer:

(3/4 x +7) - (x-10)

3/4x + 7 - x + 10

3/4x -x + 7 + 10

-1/4x + 17

Distributive Property

100

Simplify:  3(2x + 5)

ANSWER:  6x + 15

Using the distributive property, multiply each term by 3

3(2x) + 3(5) 

6x + 15

200

Simplify:  

1/2 (14x^2 - 12x + 8)

ANSWER:  7x² - 6x + 4

use the distributive property

multiply each term by 1/2

1/2(14x^2) - 1/2(12x)+1/2(8)

7x^2 -6x+4

300

Simplify: 

-5x+9(4x+12)

ANSWER:  31x + 108

Use the distributive property, then combine like terms

-5x + 9(4x) + 9(12)

-5x + 36x + 108

31x + 108

400

Simplify:

5.1(2x+4) + 7.3

Answer: 10.2x + 27.7

5.1(2x+4) + 7.3

10.2x + 20.4 + 7.3

10.2x + 27.7 

500

Simplify:

3(4a-9) - 12(a+7)

Answer: -111

3(4a) -3(9) + -12(a) + -12(7)

12a - 27 -12a - 84

12a -12a -27 -84

           -111

Factor

100

What is the greatest common factor of 144 and 9?

Answer: 9

9: 1,3,9

144: 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72, and 144 

200

Factor using the GCF:

12x + 5

Answer:  cannot be factored, the gcf is 1

300

What is the factored form of 36x + 45y?

ANSWER:  9(4x + 5y)

>> determine the greatest common factor : 9

>> divide each term by GCF: 36x/9 and 45/9

>> write in factored form with the gcf on the outside of the parentheses. 9(4x+5y)

400

What's the greatest common factor of:

10ab - 25a

Answer: 5a

10ab: 1,2,5,10,a,b

25a: 1,5,25,a

500

Factor:

4b^5 + 4b^3+16b^2

Answer: 4b² (b³ + b + 4)

4b^5 + 4b^3+ 16b^2

 gcf: 4b²

4b⁵/4b² + 4b³/4b² + 16b²/4b²

4b² (b³ + b + 4)

Miscellaneous

100

In the expression:  3x + 7, what is the coefficient?

3

The coefficient is the number that is multiplied by the variable.

200

What is the area of a rectangle with a length of 2 and width of (4x-1)?

Answer: 8x - 2

area = length x width

area = 2(4x -1)

area = 2(4x) - 2(1)

area = (8x - 2) units² 

300

What is the additive inverse of (3x - 7) ?

Answer:  -3x +7

additive inverse means the oppoisite

the opposite of (3x - 7) is -3x + 7

400

What property is show below: 

-4(3x + 4) = -12x - 16

Answer: Distributive Property

-4(3x + 4) = -12x - 16 

Distributive Property: multiply outside factor by all factors inside the parentheses 

500

What property is illustrated by:

3x + 9 = 9 + 3x

Answer: Commutative Property

Old Stuff

100

An average person blinks 50 times every 2.5 minutes.  How many times does the average person blink per hour?

Answer: 1200

50/2.5 = 20 blinks per min

20 x 60 = 1200 blinks per hour

200

What number is 75% of 150?

Answer: 112.5

of means multiply 

0.75 x 150 = 112.5

300

A group of friends has a dinner bill of $120.They want to leave a 20% tip for the server and pay an 8% sales tax. What is the total cost of their meal?

Answer: $153.60

$120(0.20) = $24 tip

$120(0.08) = $9.60 tax

Total: $120 + 24 + 9.60 = $153.60

400

Evaluate :

4/5a - 25/b - c

when a = 15, b = -1 and c = 12

Answer:

Answer:25

4/5a - 25/b - c

4/5(15) -25/-1 - 12

12 + 25 -12

25

500

What is the distance from -45 to 29?

Answer: 74

l -45 - 29 l = l -45 + -29 l = l -74 l = 74