How to solve the cubic equation: 4x + 3Y + 2Z = 20, x-4y-z = - 3, X-Y + Z = 1

How to solve the cubic equation: 4x + 3Y + 2Z = 20, x-4y-z = - 3, X-Y + Z = 1

We name these three equations as ①, ②, ③ - ② respectively, that is, X-Y + z-x + 4Y + Z = 1 + 3, and conclude that 3Y + 2Z = 4 is set as ④
③ The left and right sides of the equation equal sign are multiplied by 4 at the same time, that is, 4x-4y + 4Z = 4, which is set as ⑤. ① - ⑤, that is, 4x + 3Y + 2z-4x + 4y-4z = 20-4, which is 7y-2z = 16, which is set as ⑥, and ④ + ⑥, which is 10Y = 20, which is y = 2. Substituting the result into formula ④, we can get z = - 1, y, Z are calculated, and substituting formula ③, we can get x = 4. To sum up, x = 4, y = 2, z = - 1

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64 leaves 1 question 60 * (1 / 3 + 1 / 4) = 60 * 7 / 12 = 35 (10000 tons) 2 question 60 * 1 / 3-60 * 1 / 4 = 20-15 = 5 (10000 tons) 2 question 2 / 3-3 / 2 * 3 / 4 = 2 / 3-1 / 2 = 1 / 6 (meters) 2 question 3 / 2-3 / 4 * 2 / 3 = 2 / 3-1 / 2 = 1 / 6 (meters) 3 question 2 / 3 * (4 / 4 + 3 / 4) = 2 / 3 * 7 / 4 = 7 / 6 (meters) page 65

(1) If x = 1, the second power of the algebraic formula ax + BX + 3, then when x = 2, the value is 4, when x = 2, the value is 10, find the square of the algebraic formula ax + BX + 2
It's got to be done by 8:30, please
Sorry, is x = - 2, the value is 4

When x = - 2
∴2b+1=4a①
When ∵ x = 2
∴4a+2b=7②
Substitute (1) for (2)
4b=6
B = 3 / 2
Substituting B = 3 / 2 into (1)
4a=7
A = 7 / 4
two
The algebraic formula is 7 / 4x + 3 / 2x + 3
(you can just substitute the value of X into it.)
P.S: I can't find the value of x you asked for

If a: B = 3:4, then a is 4 / 3 of B. ()
The sooner the better. OK, I'll take the best answer right away

Judgment
The quotient of the product of two external terms of a proportional expression divided by the product of two internal terms is 1
If a: B = 3:4, then a is 4 / 3 of B

The area of a triangle is equal to that of a circle with a diameter of 10 cm. It is known that the length of the bottom edge of the triangle is 15.7 cm, and the height of the bottom edge is () cm?

1/2×15.7×h=π×(10/2)²
h=10cm
The height is (10) centimeters

Solving the equation: 3x-x divided by 2 = 8

3x-x divided by 2 = 8
2.5x=8
x=3.2

The circumference of a rectangular board is 80 decimeters, the length is 30 decimeters, how many square decimeters is its area

80 △ 2 = 40 decimeters, length widened and 40-30 = 10 decimeters, width 30 × 10 = 300 square decimeters

Simple operation: 1 / 128 + 1 / 64 + 1 / 32 +. + 1 / 4=

1/128+1/64+1/32+.+1/4
=1/128×(1+2+4+8+16+32)
=63/128

It is known that: as shown in the figure RT △ ABC ∽ RT △ BDC, if AB = 3, AC = 4. (1) find the length of BD and CD; (2) make be ⊥ DC over B over e, find the length of be

(1) In RT △ ABC, according to Pythagorean theorem: BC = AB2 + ac2 = 5, ∵ RT △ ABC ∽ RT △ BDC, ∵ abbd = bcdc = ACBC, 3bd = 5dc = 45, ∵ BD = 154, CD = 254; (2) in RT △ BDC, s △ BDC = 12be · CD = 12bd · BC, ∵ be = BD · BCCD = 154 · 5254 = 3

If ab ≠ 0, then A-B = 1 is a3-b3-ab-a2-b2 = 0______ Conditions

Because of the fact that a3-b3-ab-ab-ab-a2-a2-b2 = (a-b-1) (A2 + AB + B2) (a-b-b-1) (A2 + AB + B2) (A2 + AB + B2) \\\\\\\allof the following: because the a3-b3-ab-ab-ab-a2-b2 = (a-b-1) (a-b-b-1) (A2 + AB + AB + B2) (a-b-b-b-b-1) (A2 + ab + AB + B2) (A2 + AB + AB + B2) (a-b-b-b-b-b-b-1) (A2 + AB + AB + AB + B2) (A2 + ab-b-ab-ab-b-b-b-b-b-a2) (A2 + ab-ab-b-ab-b-b-b-b-b-b-b-b-b-b-2) (A2) (A2) (A2 + AB to sum up, A-B = 1 is a3-b3-ab-a2-b2 = 0 The answer is: necessary and sufficient