given what x=5 and y=-3, evaluate
(a) 3x - 2y
(b) 2y/3x
(a) 21
(b) - 2/5
linear expression definition
A linear expression in one variable x is an algebraic expression that contains only one term in x, with or without a constant term.
is 4x + y - 8 a linear expression
yes. it is a linear expression in two variables x and y
like terms definition
Like terms contain the same variable(s) raised to the same power.
unlike terms
Unlike terms contain the different variable(s) raised to the same power.
4x + (-7x)
-3x
-9x + 8x
-x
-3y - 4y
-7y
-6y - (-2y)
-4y
-5x + (-6y) - 3x -(-4y)
-8x - 2y
distributive law
a(b + c)
ab + ac
-(x + y)
= -x - y
-(x - y)
-x + y
7 - a(-5x + z)
7 + 5ax - az
-3(x + 2y) - 4(x - y)
-7x - 2y
5y - 2[3z - 2(y + 3z)]
9y + 6z
Factorisation of algebraic expression
-20b + 15by - 10bz
5b(3y - 4 - 2z)
factorise -6a - 24az - 4ay
-2a(3 + 12z + 2y)
is n/2 = 1/2n?
yes
is (n+1)/3 = 1/3(n + 1)?
yes
is-1/3 from -1/3x an integer?
no. its a fractional coefficient
simplify 1/2x - 1/9y - 1/8x + 11/3y
3/8x + 32/9y
simplify 2/3 [2x - 5(x - 6y)]
20y - 2x
express 1/3x + (2x - 5)/7 as a fraction in its simplest form
(13x - 15)/21