The solutions are x + 2Y + Z = 8,2x-y-z = - 3,3x + y-2z = - 1 and X + 2Y + 3Z = 4, y + Z = 1,3x + 2Z = 3

The solutions are x + 2Y + Z = 8,2x-y-z = - 3,3x + y-2z = - 1 and X + 2Y + 3Z = 4, y + Z = 1,3x + 2Z = 3

Put the formulas together, put forward all of them, and then eliminate them

Reasonable Proverbs

I don't even know how to answer proverbs

How much is the original price of a commodity, which is first reduced by 10% and then increased by 10% to buy 100 yuan?

A: the original price of this kind of commodity is 1000099 yuan

1234567890(1234567891)2−1234567890×1234567892．

Let 1234567891 = a, then 1234567890 = a-11234567892 = a + 1, the original formula = a − 1A2 − (a − 1) (a + 1) = a − 1A2 − (A2 − 1), = A-1, = 1234567891-1, = 1234567890

There are two classes in Grade 6 of a school, and now they are reorganized into three classes. One third of the original class 1 and one fourth of the original class 2 form a new class, one fourth of the original class 1 and one third of the yuan class 2 form a new class 2, and the remaining 30 form a new class 3. If the number of the new class 1 is one tenth more than that of the new class 2, how many people are there in the original class 1?

Let's suppose that there are x people in the first class and y people in the second class. New class 1: X / 3 + Y / 4, new class 2: X / 4 + Y / 3, new class 3: X - (x / 3 + Y / 4) - (x / 4 + Y / 3) = 5x / 12 + 5Y / 12 = 30x + y = 72 (1) x / 3 + Y / 4 = (x / 4 + Y / 3) × 1.1. Both sides multiply by 124x + 3Y = (3x + 4Y) × 1.1 (4x + 3Y) / (3x + 4Y) = 11 / 10 to form 40x + 30y

What is 0.75 × 5.7 + 0.75

=0.75*5.8
=4.35

The summer palace in Beijing covers an area of 290 hectares, of which the ratio of water surface area to land area is 3:1?

290 × 33 + 1 + 290 × 13 + 1, = 290 × 34 − 290 × 14, = 217.5-72.5, = 145 (HA). A: the water area of the summer palace is 145 ha more than the land area

Happy learning all the words in Volume 2 of grade 5 of primary school
The first word at the beginning is good, written in Chinese,

As shown in the figure, in the plane rectangular coordinate system, we know that the vertices of the right angled trapezoid oabc are o (0,0), a (9,0), B (6,4), C (0,4),

36366

-125 times 41 + 125 times (- 27) minus 5 times 32 minus 21 times (1 + 1 / 3 + 7 / 2 minus 4 / 21) =?
Simple calculation

Two out of seven in the middle
simple form
=-125x41-125x27-125x32-21x(1+1/3+2/7-4/21)
=-125x(41+27+32)-(21x1+21x1/3+21x2/7-21x4/21)
=-125x100-(21+7+6-4)
=-12500-30
=-12530