Question

2 1/8 * 5 2/4 ; 7 1/8 - 2 9/10 ; 7,2:0,00009,8/9 : 24/72

Answer 1

2 1/8 x 5 2/4=17/8 x 22/4=187/16
7 1/8 - 2 9/10=57/8-29/10=570/80 - 232/80=338/80=169/40
7,2 :0,00009=80000
8/9 : 24/72=8/9 x72/24=8/3

Answer 2

Let's solve each of the mathematical expressions step by step:

1. 2 1/8 * 5 2/4: To multiply mixed numbers, we first convert them to improper fractions and then perform the multiplication.

2 1/8 can be written as an improper fraction as follows: 2 1/8 = (8 * 2 + 1)/8 = 17/8

Similarly, 5 2/4 can be written as: 5 2/4 = (4 * 5 + 2)/4 = 22/4

Now we can multiply the fractions: (17/8) * (22/4) = (17 * 22)/(8 * 4) = 374/32

To simplify the fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 2: 374/32 = (187 * 2)/(16 * 2) = 187/16

So, 2 1/8 * 5 2/4 equals 187/16.

2. 7 1/8 - 2 9/10: To subtract mixed numbers, we follow a similar process as before.

7 1/8 can be written as an improper fraction: 7 1/8 = (8 * 7 + 1)/8 = 57/8

2 9/10 can be written as: 2 9/10 = (10 * 2 + 9)/10 = 29/10

Now we can subtract the fractions: 57/8 - 29/10

To subtract fractions with different denominators, we need to find a common denominator. In this case, the least common multiple (LCM) of 8 and 10 is 40.

Multiplying the first fraction by 5/5 and the second fraction by 4/4 to have the same denominator: (57/8) * (5/5) - (29/10) * (4/4) = (285/40) - (116/40)

Now we can subtract the fractions: (285/40) - (116/40) = (285 - 116)/40 = 169/40

So, 7 1/8 - 2 9/10 equals 169/40.

3. 7.2 : 0.00009,8/9 : 24/72: Let's solve each expression separately:

7.2 : 0.00009: Dividing 7.2 by 0.00009 results in: 7.2 / 0.00009 = 80000

8/9 : 24/72: To divide fractions, we multiply the first fraction by the reciprocal of the second fraction: (8/9) / (24/72) = (8/9) * (72/24)

Now we can simplify the fraction: (8/9) * (72/24) = (8 * 72)/(9 * 24) = 576/216

To simplify this fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 8: 576/216 = (576/8) / (216/8) = 72/27 = 8/3

So, 7.2 : 0.00009 equals 80000, and 8/9 : 24/72 equals 8/3.