Variables and Expressions
6a +3b = 4
Equation.
Evaluate the expression when b = 4
2b
2 x 4
= 8
I'm going to Coles! I am buying 10 items, but only 5 items fit per bag. How many bags will I need?
Bags = number of items (N) divided by items per bag (I).
N = 10
I = 5
2
Simplify the following 2a + 4a
6a
Expand: 5(a -2)
=5a - 10
List ALL the variables
6a + 3b - 2y
a b y
Evaluate the expression 4b - a when b = 2 and a = 3
=8-3
=5
I went to coles and I have the following items in my basket.
A (eggs) = 10
B (bread) = 5
C (juice) = 8
How much money will I need?
=a + 3b + 5c
10 + 3 x 5 + 5 x 8
= 10 + 15 + 40
= 65
Simplify the following 9u - 7u + 3z
3u + 3z
Expand: -3(a - b)
= -3a + 3b
What is the coefficient?
3a + 5
Evaluate the expression 10ab - b when a = 3 and b =6
10 x 3 x 6 - 6
=30 x 6 - 6
= 180 - 6
= 174
The formula F = 9C/5 + 32 is used to convert temperatures in degrees celsius (C) to degrees farenheit. Use the formula to convert 29 degrees celsius to degrees farenheit.
9 x 29/5 + 32
= 84.2
Simplify 8a + a^2 + 3b - 5b
8a + a^2 - 2b
= 2a^2 + 6ab
I think of a number and add 3, and divide the answer by 10. Write an expression to show this.
n + 3 / 10
Evaluate the following expressions when x =-2 and y=-5
2y - 3x
2 x - 5 - 3 x - 2
= -10 + 6
= -4
The formula C = 5F - 160/9 converts farenheit (F) to degree celsius. Convert 32 degrees farenheit to celsius.
=160 - 160 / 9
= 0 degrees celsius.
Simplify 3hdw + 6hd + 7d - 4hd + 8 - 2d
=3dhw + 2dh + 5d + 8
Expand and collect like terms: 3(r-4) - 8r
=3r - 23 - 8r
=-5r - 12
There are a apples and p pears in one fruit dish. Write this as an expression. Write an expression to show this.
a + p
-5y^2
-5 x -5^2
= - 5 x 25
=-125
The time (T) needed for an elevator of power (W) kilowatts to lift (M) kilograms, (H) metres is t = mh/25w. If w = 20, the time it takes to list a group of people with a total mass of 400kg to a height of 50metres is...
= 400 x 50/25 x 20
=20,000/500
=40 seconds
Simplify 6a^3 - 8a^2 - 4a - 5a - 4a^3 - 61
=2a^3 - 8a^2 - 9a - 61
Expand and collect like terms: 5(a + 6b) + a(9-10a)
=5a + 30b + 9a - 10a^2
=14a + 30b - 10a^2