Examples with solutions for Multiplication and Division of Signed Mumbers: Dividing numbers with different signs

Exercise #1

(+10):(5)= (+10):(-5)=

Video Solution

Step-by-Step Solution

Due to the fact that we are dividing a positive number by a negative number, the result must be a negative number:

+:= +:-=-

Therefore:

(10:5)=2 -(10:5)=-2

Answer

2 -2

Exercise #2

Solve the following problem:

(+24):(0.4)= (+24):(-0.4)=

Video Solution

Step-by-Step Solution

Given that we are dividing a positive number by a negative number, the result must be a negative number:

+:= +:-=-

First, let's convert 0.4 to a simple fraction:

0.4=410 0.4=\frac{4}{10}

Now we have the problem:

(24:410)= -(24:\frac{4}{10})=

Let's convert the division to multiplication, remembering to switch the numerator and denominator:

(24×104)= -(24\times\frac{10}{4})=

We'll simplify by 4 as follows:

(6×10)=6×10=60 -(6\times10)=-6\times10=-60

Answer

60 -60

Exercise #3

(+3):(0.05)= ? (+3):(-0.05)=\text{ ?}

Video Solution

Step-by-Step Solution

Firstly we need to realise that since we are dividing two negative numbers, the result must be a positive number.

+:= +:-=-

Next, let's convert 0.05 into a simple fraction:

0.05=5100 -0.05=-\frac{5}{100}

We are left with:

(3:5100)= -(3:\frac{5}{100})=

Then let's convert the division into multiplication, remembering to switch the numerator and denominator:

(3×1005)= -(3\times\frac{100}{5})=

Finally we can continue solving to find the answer:

(3×20)=60 -(3\times20)=-60

Answer

60 -60

Exercise #4

Solve the following expression:

(+0.9):(0.15)= (+0.9):(-0.15)=

Video Solution

Step-by-Step Solution

Since we are dividing a positive number by a negative number, the result must be a negative number:

+:= +:-=-

First, let's convert the numbers in the exercise to simple fractions:

0.9=910 0.9=-\frac{9}{10}

0.15=15100 0.15=\frac{15}{100}

Resulting in the following exercise:

(910:15100)= -(\frac{9}{10}:\frac{15}{100})=

Let's convert the division to multiplication, don't forget to switch between numerator and denominator:

(910×10015)= -(\frac{9}{10}\times\frac{100}{15})=

Let's reduce by 10 and obtain the following:

(9×1015)= -(9\times\frac{10}{15})=

Let's combine into one exercise:

(9×1015)=9015 -(\frac{9\times10}{15})=-\frac{90}{15}

Let's break down 90 into a multiplication exercise:

3×3015= -\frac{3\times30}{15}=

Let's reduce the numerator and denominator by 15 and obtain:

3×2=6 -3\times2=-6

Answer

6 -6

Exercise #5

200:200200= 200:-200\cdot200=

Video Solution

Step-by-Step Solution

Let's solve the exercise from left to right.

First, we'll write the division problem in the form of a fraction:

200200×200= \frac{200}{-200}\times200=

We should note that we are dividing a positive number by a negative number, so the result will necessarily be a negative number:

200200×200= -\frac{200}{200}\times200=

Let's simplify the 200 and we get:

200 -200

Answer

200 -200

Exercise #6

Solve the following equation:

38:(4)12:(3)= 38:(-4)\cdot12:(-3)=

Video Solution

Step-by-Step Solution

Let's begin by writing the two division exercises as a multiplication of two simple fractions:

(38:(4))×(12:(3))= (38:(-4))\times(12:(-3))=

384×123= \frac{38}{-4}\times\frac{12}{-3}=

Let's proceed to combine them into one exercise:

38×124×3= \frac{38\times12}{-4\times-3}=

Note that in the denominator of the fraction we are multiplying two negative numbers, therefore the result must be positive:

38×124×3= \frac{38\times12}{4\times3}=

Let's now break down the 12 in the fraction's numerator into a multiplication exercise:

38×4×34×3= \frac{38\times4\times3}{4\times3}=

Finally let's reduce the multiplication exercise 4X3 in the numerator and denominator and we should obtain the following:

38 38

Answer

38 38

Exercise #7

134:8= -13\cdot4:-8=

Video Solution

Step-by-Step Solution

Let's solve the exercise from left to right.

Note that we are first multiplying a negative number by a positive number, therefore the result must be a negative number:

13×4=52 -13\times4=-52

Now we got the exercise:

52:8= -52:-8=

Let's write the exercise as a simple fraction:

528= \frac{-52}{-8}=

Note that we are dividing between two negative numbers, therefore the result must be a positive number:

528= \frac{52}{8}=

Let's convert it to an addition exercise:

6+48= 6+\frac{4}{8}=

Let's break down the 8 into a multiplication exercise:

6+44×2= 6+\frac{4}{4\times2}=

Let's reduce the 4 in both eight and the fraction's denominator:

6+12=612 6+\frac{1}{2}=6\frac{1}{2}

Answer

612 6\frac{1}{2}

Exercise #8

+400(4):16:6= +400\cdot(-4):-16:-6=

Video Solution

Step-by-Step Solution

Let's write the exercise in the following form:

400×(4)16:6= \frac{400\times(-4)}{-16}:-6=

Let's factor -16 in the denominator as a multiplication exercise:

400×(4)4×(4):6= \frac{400\times(-4)}{4\times(-4)}:-6=

Let's reduce -4 in both the numerator and denominator and get:

4004:6= \frac{400}{4}:-6=

Let's factor the 100 in the numerator as a multiplication exercise:

100×44:6= \frac{100\times4}{4}:-6=

Let's reduce the 4 in both the numerator and denominator and get:

100:6= 100:-6=

Let's write the exercise as a fraction:

1006= \frac{100}{-6}=

Note that we are dividing a positive number by a negative number, therefore the result must be negative.

Let's factor the 100 as an addition exercise:

96+46= -\frac{96+4}{6}=

Let's write the exercise in the following way:

(966+46)= -(\frac{96}{6}+\frac{4}{6})=

Let's solve the first fraction and in the second fraction let's factor the numerator and denominator as multiplication exercises:

(16+2×22×3)= -(16+\frac{2\times2}{2\times3})=

Let's reduce the 2 in both the numerator and denominator:

(16+23)= -(16+\frac{2}{3})=

Let's pay attention to the appropriate sign since we are multiplying by a negative number:

1623 -16\frac{2}{3}

Answer

1623 -16\frac{2}{3}