Question

A) 1/7*14/2+1/8+2/9*0.3 Б) 13/16*1/26-7/8*(1/5+4/7)

Answer 1

Вот вроде правильно решила

Answer 2

A) Let's solve the expression step by step:

1/7 * 14/2 + 1/8 + 2/9 * 0.3

To simplify the expression, we can start by performing the multiplications and divisions:

(1/7) * (14/2) + (1/8) + (2/9) * 0.3 = (1 * 14) / (7 * 2) + 1/8 + (2 * 0.3) / 9 = 14/14 + 1/8 + 0.6/9 = 1 + 1/8 + 0.067

Now, we can add the fractions and simplify further:

1 + 1/8 + 0.067 = 1 + 0.125 + 0.067 = 1.192

Therefore, the value of the expression 1/7 * 14/2 + 1/8 + 2/9 * 0.3 is 1.192.

B) Let's solve the expression step by step:

(13/16) * (1/26) - (7/8) * ((1/5) + (4/7))

First, we perform the additions within the parentheses:

(7/8) * ((1/5) + (4/7)) = (7/8) * ((7/35) + (20/35)) = (7/8) * (27/35) = (7 * 27) / (8 * 35) = 189/280

Now we substitute this value back into the main expression:

(13/16) * (1/26) - (189/280)

To subtract fractions, we need a common denominator:

(13/16) * (1/26) - (189/280) = (13/16) * (1/26) - (189/280) * (1/1)

Now, we can multiply the numerators and denominators:

(13 * 1) / (16 * 26) - (189 * 1) / (280 * 1) = 13/416 - 189/280

To subtract fractions, we need a common denominator. In this case, the least common multiple of 416 and 280 is 2,240:

(13/416) * (5/5) - (189/280) * (8/8) = 65/2,080 - 1,512/2,240

Now, we can subtract the fractions:

65/2,080 - 1,512/2,240 = (65 * 2,240 - 1,512 * 2,080) / (2,080 * 2,240) = (145,600 - 3,145,600) / 4,659,200 = -2,999,000 / 4,659,200

This fraction cannot be simplified further. Therefore, the value of the expression (13/16) * (1/26) - (7/8) * ((1/5) + (4/7)) is approximately -0.6443.