Texas Success Initiative (TSI) - Lone Star College

Texas Success Initiative (TSI)

MATH REVIEW

Algebra Review

ALGEBRA & FUNCTIONS

Variables and Algebraic Expressions The sum of a number and 5 means:

m + 5 or 5 + m

The number diminished or subtracted by 7 means:

m ? 7

Ten times a number means:

10m

z divided by 3 means:

z / 3

Algebraic Expressions

Key words which denotes addition

sum, plus, greater than, more than, larger than, rise, increase, gain

Key words which denotes subtraction

difference, minus, less than, smaller than, fewer than, decrease, drop, reduce, diminish, lose

Key words which denotes multiplication

multiplied by, times, product, twice

Key words which denotes division

quotient, divided by, ratio, half

Solving Equations

Examples:

If 3t ? 7 = 5t, then 6t = ?

Solve for t; then find 6t

3t ? 5t = 7

- 2t = 7 t = - (7 / 2)

Thus, 6t = 6(-7/2) = -21

Solving Equations

Examples:

If (x-1)/x =20, then x = ? x-1 = 20x x-20x = 1 -19x = 1; thus x= -1/19

Ratios & Proportions

Ratio is a way of comparing two or more variables. It is written as a:b or a/b Proportions are written as two ratios in terms of fractions

equal to each other. Ex Solve this proportion for s:

p is to q as s is to t p/q = s/t

s = t(p/q)

Solving Equations

Examples: Variables x and y are directly proportional, and y=2 when

x=3.What is the value of y when x=9? y x y = kx where k is a constant 2 = k(3) ; k= 2/3 y=(2/3)x

Now, we can substitute x=9 and find y: y = (2/3) 9 = 6

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download