x+y=-1 z+x=0 y+z=1 x+y=-1 z+x=0 y+z=1

x+y=-1 z+x=0 y+z=1 x+y=-1 z+x=0 y+z=1

x+y=-1 （1）
z+x=0 （2）
y+z=1 （3）
(1) (2) Y-Z = - 1 (4)
(4) If + (3), 2Y = 0
y=0
Substitute (1) to get x = - 1
Substituting (3) gives z = 1

How to solve the equation 3x * [1 / (4 + x)] = - 3

Multiply both sides by 4 + X
Divide by three
x=-(4+x)
x=-4-x
2x=-4
x=-2

1 / 6 * (6.75 / 5 / 12-2.4 + 4 and 1 / 4 * 2 and 2 / 5) - 1 and 1 / 8-0.875
9999*2222+3333*3334=
（1*3*24+2*6*48+3*9*72）/（1*2*4+2*4*8+3*6*12）=

875 = 1 / 6 × (27 / 4 × 12 / 5-12 / 5 + 17 / 4 × 12 / 5) - 9 / 8-7 / 8 = 1 / 6 × 12 / 5 - (27 / 4-1 + 17 / 4 × 12 / 5) - (9 / 8 + 7 / 8) = 1 / 6 × 12 / 5 × 10-2 = 4-2 = 29999 × 2222 + 3333 × 3334 = 3333 × (3 × 2222) + 3333 × 3334 = 333

Write three different formulas of X & # 178; - 4x + 16, quadratic trinomial
Read the following material: matching a quadratic trinomial (or part of it) in the form of AX2 + BX + C into a complete square is called matching method. The basic form of the formula is the inverse application of the complete square formula, that is, A2 ± 2Ab + B2 = (a ± b) 2
for example
x^2-4x+2=（x-2）^2-2，
x^2-4x+2=（x+ 2）^2-（2 2+4）x，
x^2-4x+2=（ 2x- 2）^2-x^2；

x²-4x+16
=(x²-4x+4)+12
=(x-2)²+12

The school assigned 360 science and technology books to class A, class B and class C. 1 / 2 of class A is equal to 1 / 3 of class B and 1 / 4 of class C. how many books do class A, class B and class C get

Suppose class a gets x, then class B gets 3x, and class C gets 4x. Then, according to the total number of 360, there is
x+3x+4x=360-->x=45
45 in class A, 135 in class B and 140 in class C
Children should work hard!

When x=_____ The formula (x + 3) ² + 5 has a minimum value, which is_____ When y=_____ Tense, form
When x=_____ The formula (x + 3) ² + 5 has a minimum value, which is_____ ；
When y=_____ The formula 7 - (y + 1) &# + 5 has a maximum value, which is_____ .

-3 15
-1 12

435 - (135 + 58) with simple calculation!

435-（135+58）
=（435-135）-58
=300-58
=242

(a-b + B of a + B & #) * a + B of a

The original formula = [(a-b) (a + b) + B & # 178;] / (a + b) * (a + b) / A
=(a²-b²+b²)/(a+b)*(a+b)/a
=a²/(a+b)*(a+b)/a
=a

There is a bottle of alcohol, the first time poured out 2 / 3 and 80 grams, and then poured back 140 grams
The second time, pour out 3 / 4 of the alcohol in the bottle. At this time, 90 grams of alcohol are left in the bottle. How many grams of the original alcohol?
The teacher asked me to talk about how to solve this problem

90 / (1-3 / 4) = 360 G
360-140 = 220 G·
(500 + 80) / (1-2 / 3) = 900g
Hope to help you!
Please accept

How to divide 5 out of 16 and 9 out of 28

How to divide 5 out of 16 and 9 out of 28
The least common multiple of 16 and 28 is 112;
So 5 / 16 = 35 / 112; 9 / 28 = 36 / 112;
If you don't understand this question, you can ask,