# LESSON 1 - VARIABLE EXPRESSIONS

Use this formula to convert the temperature in Fahrenheit (°F) to Celsius ( °C)

Use the formula to convert to 68 degrees Fahrenheit to Celsius.

Now try it the other way.Transform the formula to find Fahrenheit temperature in terms of Celsius temperature.

Use this formula to convert the temperature in Celsius ( °C) to Fahrenheit (°F)

Use the formula to convert to - 25 degrees Celsius to Fahrenheit.

a + b           a added to b

a – b           b subtracted from a

a xb         a multiplied by b

a : b            a divided by b

(.)     in brackets/parentheses

[.]     in square brackets

{.}    in twirly brackets

### USEFUL PHRASES

evaluate numerical expression – obliczyć wartość wyrażenia

evaluate for the given values of variables – obliczyć wartość wyrażenia dla danych liczb

expression involving parentheses – wyrażenie zawierające nawiasy

order of operations – kolejność działań

combining like terms – redukcja wyrazów podobnych

simplify as far as possible – maksymalnie uprościć

rational expression – wyrażenie wymierne

factorise – rozłożyć na czynniki

### Label true or false

If an expression does not involve any grouping symbols, all multiplications and divisions should be performed in order from left to right before any addition and subtraction. (T/F)

### Select the phrase that best completes the sentence

must be, cannot be, can be but needn’t be.

To evaluate correctly the expression the rules for order of operations ……… applied.

There ……… one/any of the operations of addition, subtraction, multiplication and division in

any algebraic expression.

To evaluate an algebraic expression variables ……… substituted with numbers.

### TIME FOR PROBLEMS

1) Write variable expressions

• Write an expression for the quotient of 46 and k. (quotient - iloraz - wynik dzielenia)
• Write an expression for the sum of r and 130.
• Write an expression for 367 less d.
• Write an expression for p multiplied by 241.
• Write an expression for u minus 295.
• Write an expression for 10 times b.
• Write an expression for 377 fewer than m.
• Write an expression for 142 divided by w.
• Write an expression for 48 increased by g.
• Write an expression for 57 more than k.
• Write the cube of the sum of squares of a and b.
• Write the product of the sum and difference of a and b.

2) If possible, simplify by combining like terms: 44hj + 23h3 + 28hj + 46hj =

…………………………………

3)n Evaluate the expression for v = - 1.

-12 + 8v = ………………………..

Formulas.pdf