Question

(9 1/4 - 7 2/5) * 2 1/2- 1 1/2

Answer 1

Тот же самый пример, только в десятичных

(9,25-7,4)•2,5-1,5=1,85•2,5-1,5=4,625-1,5=3,125

Можно было решать обычными дробями, тогда получится

(9¼-7 2/5)•2½-1½=(8 5/4-7 2/5)•2½-1½=

=(8 25/20-7 8/20)•2½-1½=1 17/20•2½-1½ =37/20•5/2-1½=37/8-1½=37/8-12/8=25/8=3⅛=3,125

Answer 2

To simplify the expression (9 1/4 - 7 2/5) * 2 1/2 - 1 1/2, let's break it down step by step.

First, let's simplify the subtraction inside the parentheses:

9 1/4 - 7 2/5 = (36/4 + 1/4) - (35/5 + 2/5) = 37/4 - 37/5

To subtract these fractions, we need a common denominator, which is the least common multiple (LCM) of 4 and 5, which is 20.

37/4 - 37/5 = (37 * 5)/(4 * 5) - (37 * 4)/(5 * 4) = 185/20 - 148/20 = (185 - 148)/20 = 37/20

Next, let's simplify the multiplication:

(37/20) * (2 1/2) = (37/20) * (5/2) = (37 * 5)/(20 * 2) = 185/40 = (37 * 5)/(8 * 5) = 37/8

Finally, let's subtract 1 1/2 from the result:

37/8 - 1 1/2 = (37/8) - (16/8 + 1/2) = 37/8 - 17/8 - 1/2 = (37 - 17)/8 - 1/2 = 20/8 - 1/2 = 10/4 - 2/4 = 8/4 = 2

Therefore, (9 1/4 - 7 2/5) * 2 1/2 - 1 1/2 simplifies to 2.