math test revision

Answer explanation

[z + 11 = 35 - 5z]

-z -z

[11 = 35 - 6z]

-35 -35

[-24 = -6z]

÷-6 ÷-6

[4 = z]

OR

[z + 11 = 35 - 5z]

+5z +5z

[6z + 11 = 35]

-11 -11

[6z = 24]

÷6 ÷6

[z = 4]

4.2 simultaneous equations

-

solve these simultaneous equations

6x + 7y = 49

3x - 7y = 14

write your answer like this (without speech marks and without stuff in brackets)

“(what x is),(what y is)”

for e.g

“4,9”

(a)  

Answer explanation

(A) 6x + 7y = 49

(B) 3x - 7y = 14

A + B

9x = 63

÷9 ÷9

x = 7

SUBS

6x + 7y = 49

substitute x

6(7) + 7y = 49

simplify

42 + 7y = 49

-42 -42

7y = 7

÷7 ÷7

y = 1

4.3 inequalities

-

Length AB is shorter than length AC

write an inequality to show this and solve it

• x < 18

• x > 4

• x > 18

• x < 4

Answer explanation

3x - 7 < 4x - 11

+7 +7

3x < 4x - 4

-4x -4x

-x < -4

÷-1 ÷-1

x > 4

5.1 calculating angles

-

work out the value of x

• 120

• 105

• 65

• 140

Answer explanation

5.2 Interior angles in polygons

-

What does x equal to?

• 145

• 125

• 290

• 100

Answer explanation

720 - (150+130+150+90) = 2x

720 - 520 = 2x

200 = 2x

100 = x

5.3 Exterior angles of polygons

-

This is a challenging question but you can do it!

• A

• B

• C

• D

Answer explanation

32+8x+6+180−(10x+16)=180

Simplify both sides of the equation.

32+8x+6+180−(10x+16)=180

32+8x+6+180+−10x+−16=180

(8x+−10x)+(32+6+180+−16)=180

(Combine Like Terms)

−2x+202=180

−2x+202=180

Subtract 202 from both sides.

−2x+202−202=180−202

−2x=−22

Divide both sides by -2.

−2x−2=−22−2

x=11

5.5 Pythagoras’ theorem and

7.1 area/circumference of a circle

-

What is the perimeter of this shape?

round the answer to a whole centimeter

(You Are Allowed A Calculator)

• 43

• 37

• 47

• 35

Answer explanation

7.2 Areas of compound shapes

-

Work out the shaded area (3 s.f)

(You Are Allowed A Calculator)

• 53.4

• 21.6

• 35.9

• 25.5

Answer explanation

7.3 Large and small units

-

What is the order of the prefixes? (smallest to largest)

• nano, micro, milli, hecto, centi, kilo

• nano, micro, milli, centi, kilo, hecto

• micro, nano, milli, centi, hecto, kilo

• nano, micro, milli, centi, hecto, kilo

• kilo, hecto, centi, milli, micro, nano

Answer explanation

8.1 Fractions and recurring decimals

-

Select the fraction that is recurring:

Answer explanation

12/60 = 1/5 = 0.2

36/60 = 3/5 = 0.6

45/60 = 9/10 = 0.9

55/60 = 11/12 = 0.916˙ =

0.916666666…

3 21/60 = 7/20 = 0.35