4 x − 5 = 7 4x-5=7 4x−5=7. Add 5 to both sides. Simplify 7 + 5 7+5 7+5 to 12. Divide both sides by 4.

The idea in solving equations is to get the variable by itself on one side of the equation. We do this by “undoing” what is done to x, or doing the opposite. This problem is x divided by 5 equals negative 7. The x is divided by 5, and we have to do the opposite, that is, we have to multiply by 5.

The first step when multiplying fractions is to multiply the two numerators. The second step is to multiply the two denominators. Finally, simplify the new fractions. The fractions can also be simplified before multiplying by factoring out common factors in the numerator and denominator.

The reason we cross multiply fractions is to compare them. Cross multiplying fractions tells us if two fractions are equal or which one is greater. This is especially useful when you are working with larger fractions that you aren’t sure how to reduce. Let’s take a look at some numerical examples.

The result is the numerator of the answer. Step 2: Multiply the denominators of each fraction by each other (the numbers on the bottom)….Dividing Fractions

1. Step 1: Take the reciprocal of the divisor.
2. Step 2: Multiply the numerators.
3. Step 3: Multiply the denominators.
4. Step 4: Simplify the answer.

Multiply by 7 😀 The second digits of the answers for numbers 1 to 10 do not repeat. So, there’s really no secret trick for multiplying by 7.

A Mathemagical Trick Start by thinking of a number, any number. Now, multiply that number by 9. If the result is a multi-digit number, add its digits together to come up with a new number. If that new number is still a multi-digit number, add its digits together to come up with yet another new number.

You can also use repeated addition, or adding numbers over and over again, to multiply by 3. For example, if you had the problem 3 x 2, you could add 3 two times and get the answer. So, 3 + 3 = 6 which is the same thing as 3 x 2 = 6.

Here’s the trick: Any time you square a two-digit number that ends in 5, the last digits of the answer will be 25 and the digits before that are given by multiplying the first digit of the number by the number that’s one greater.

In mathematics, we call multiplying a number by itself “squaring” the number. We call the result of squaring a whole number a square or a perfect square. A perfect square is any number that can be written as a whole number raised to the power of 2. For example, 9 is a perfect square.

What do you get when you multiply all of the numbers on a phone’s number pad? Zero.

The ‘4 rules’ (addition, subtraction, multiplication and division) are at the heart of calculation and problem solving.

When we have to multiply three or more numbers together, we start by multiplying any two of the factors together, then we multiply this product by another factor. If there are more than three numbers, we keep going until we have used all the factors.

To multiply by 12, we add a zero to the number we’re going to multiply and then we add double the original number to the result.

36 = 1 x 36, 2 x 18, 3 x 12, 4 x 9, or 6 x 6.

There are overall 8 factors of 30 among which 30 is the biggest factor and 1, 2, 3, 5, 6, 10, 15, and 30 are positive factors. The sum of all factors of 30 is 72. Its Prime Factors are 1, 2, 3, 5, 6, 10, 15, 30 and (1, 30), (2, 15), (3, 10) and (5, 6) are Pair Factors.

Common Factors of 10 and 30: 1, 2, 5, 10.

The first 10 multiples of 30 are: 0, 30, 60, 90, 120, 150, 180, 210, 240, 270.

The number 30 can be written in prime factorization as 2 x 3 x 5. All of the factors are prime numbers.