Introduction for 7th grade pre algebra math:
Already we study simple algebraic expressions like x + 3, 10y – 5 and so on. In 7th grade, we see how these expressions are useful in formulating pre algebra problems. We also see some examples of several expressions in this chapter on simple equations. Expressions are a central concept in pre algebra. 7th grade pre algebra Chapter is committed to algebraic expressions. When you study this 7th grade Chapter, you will know how algebraic expressions are formed, how they combined, how to find their values and how they used.
7th grade pre algebra math:
When terms have the same algebraic factors, they are like terms. An expression with only one term is called a monomial; For example, 7xy, – 5m, 3z, 4 etc.,
An expression contain two unlike terms is called a Binomial. For example, x + y, m – 5, mn + 4m, a2 – b2 are binomials.
The expression 10pq is not a binomial; because it contain one term, so it is a monomial.
The expression (a + b + 5) is not a binomial.
Since it contain three terms.
An expression which contains three terms is called a Trinomial; For example,
The Algebraic Expressions x + y + 7, ab + a +b,
3x2 – 5x + 2, m + n + 10 are trinomials.
The expression ab + a + b + 5 is, however not a trinomial; it contains four terms and not three. The expression x + y + 5x is not a trinomial as the terms x and 5x are like terms. Generally, an Algebraic Expression with one or more terms is known as polynomial. Thus a monomial, binomial and trinomial are all polynomials.
Adding and subtracting like terms of 7th grade pre algebra:
The simplest expressions are monomials. In pre algebra monomial consist of only one term. To start 7th grade pre algebra we shall learn how to add or subtract like terms. Is this topic what are variables hard for you? Watch out for my coming posts.
7th grade pre algebra math problems:
Example 1:
solve: 4x + 5x
Solution:
4x + 5x = (4 × x) + (5 × x)
Let us add 4x and 5x. We know x is a number and so also are 4x and 5x.
4x + 5x = (4 × x) + (5 × x)
= (4 + 5) × x (using distributive law)
9x = 9 × x
Similarly 3x + 4x = 7x
2) Let us subtract 4x from 7x.
7x– 4x = (7 × x) – (4 × x)
(7 – 4) × x = 3 × x
= 3x
(or) 7x – 4x = 3x.
Similarly 6x - 2x = 4x
Example 2:
solve: 2x + 4x + 3
Solution:
Take f(x) = 2x + 4x + 3
Put f(x) = 0
2x + 4x + 3 = 0
6x + 3 = 0
Subtract 3 on both side
6x + 3 - 3 = 0 -3
6x = - 3
Divide by 6 on both side
`(6x)/(6)` = `- 3/6`
x = `-1/2`
Already we study simple algebraic expressions like x + 3, 10y – 5 and so on. In 7th grade, we see how these expressions are useful in formulating pre algebra problems. We also see some examples of several expressions in this chapter on simple equations. Expressions are a central concept in pre algebra. 7th grade pre algebra Chapter is committed to algebraic expressions. When you study this 7th grade Chapter, you will know how algebraic expressions are formed, how they combined, how to find their values and how they used.
7th grade pre algebra math:
When terms have the same algebraic factors, they are like terms. An expression with only one term is called a monomial; For example, 7xy, – 5m, 3z, 4 etc.,
An expression contain two unlike terms is called a Binomial. For example, x + y, m – 5, mn + 4m, a2 – b2 are binomials.
The expression 10pq is not a binomial; because it contain one term, so it is a monomial.
The expression (a + b + 5) is not a binomial.
Since it contain three terms.
An expression which contains three terms is called a Trinomial; For example,
The Algebraic Expressions x + y + 7, ab + a +b,
3x2 – 5x + 2, m + n + 10 are trinomials.
The expression ab + a + b + 5 is, however not a trinomial; it contains four terms and not three. The expression x + y + 5x is not a trinomial as the terms x and 5x are like terms. Generally, an Algebraic Expression with one or more terms is known as polynomial. Thus a monomial, binomial and trinomial are all polynomials.
Adding and subtracting like terms of 7th grade pre algebra:
The simplest expressions are monomials. In pre algebra monomial consist of only one term. To start 7th grade pre algebra we shall learn how to add or subtract like terms. Is this topic what are variables hard for you? Watch out for my coming posts.
7th grade pre algebra math problems:
Example 1:
solve: 4x + 5x
Solution:
4x + 5x = (4 × x) + (5 × x)
Let us add 4x and 5x. We know x is a number and so also are 4x and 5x.
4x + 5x = (4 × x) + (5 × x)
= (4 + 5) × x (using distributive law)
9x = 9 × x
Similarly 3x + 4x = 7x
2) Let us subtract 4x from 7x.
7x– 4x = (7 × x) – (4 × x)
(7 – 4) × x = 3 × x
= 3x
(or) 7x – 4x = 3x.
Similarly 6x - 2x = 4x
Example 2:
solve: 2x + 4x + 3
Solution:
Take f(x) = 2x + 4x + 3
Put f(x) = 0
2x + 4x + 3 = 0
6x + 3 = 0
Subtract 3 on both side
6x + 3 - 3 = 0 -3
6x = - 3
Divide by 6 on both side
`(6x)/(6)` = `- 3/6`
x = `-1/2`
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