Substitution

If x = 5, find the value of 7x-1.

• 34

• 36

• 35

• 37

If y = 7, find the value of 2(y+4).

• 11

• 22

• 20

• 12

What is the value of 7a + 3 if a = -2?

• -11

• 11

• 10

• -10

What is the value of -3y - 9 if y = -8?

• 15

• -15

• 14

• -14

Which choice shows substitution correctly?

• 3x - (-6x +3) = 10

• 3(-6x + 3) - y = 10

Which choice shows substitution correctly?

• 3x - (-6x +3) = 10

• 3(-6x + 3) - y = 10

Work out the value of the following expressions when a = 3, b = 4 and c = 5.
2a² + c²   

• 22

• 34

• 68

• 43

Work out the value of the expression when a = 3, b = 4 and c = 5.

• 3

• 1   1/3

• 4

• 1/3

Work out the value of the expression when x = 3, y = – 2 and z = – 4.

• 1

• -1

• 1/5

• -6

3(2c - 5)

• 6c - 15

• 6c + 15

• 6c + 15

• -6c - 15