Given 2x + y = 4, the value of 6x + 3Y is

∵2X+Y=4 ∴6X+3Y=3（2X+Y）=3×4=12

Given 2x-y = - 3, then the value of (y-2x) - 6x + 3Y + 7 is___

(Y-2X)-6X+3Y+7
=-（2X-Y）-3（2X-Y）+7
=3+3*3+7
=19

As shown in the figure, in rectangular ABCD, AC and BD intersect at points o, BF ⊥ AC, AF ⊥ BD, and the perpendicular feet are e and f respectively

Because it's a rectangle, all four corners are right angles
Angle BAF = 90 degrees - angle ABF = angle CBD = angle BDA = angle DAE = 90 degrees - angle BAE = angle Abe
Because BAF = Abe, AEB = AFB, ab = ab
So the triangle AEB is equal to the triangle BFA
So AE = BF

1. Simple calculation: 47 / 48 times 37 2. 8 / 10 times 5 / 11 plus 3 / 11 times 5 / 27

1. The original formula = (1-48 / 1) times 37 = 37-48 / 37 = 36 + 48 / 11
2. The original formula is 98% by 5% 11 + 3% by 5% 11
= (98 / 9 + 3 / 27) times 5 / 11
= 11 times five out of eleven = 5

A point of 2.5 unit length from the origin to the right represents a rational number (), and a point of 5 / 6 unit length from the origin to the left represents a rational number ()

A point of 2.5 unit length from the origin to the right represents a rational number (2.5), and a point of 2 and 5 / 6 unit length from the origin to the left represents a rational number (- 2 and 5 / 6)

As shown in the figure, O is the diagonal intersection of rectangular ABCD, DF bisects ∠ ADC, AC intersects at point E, BC intersects at point F, ∠ BDF = 15 °, then ∠ COF=______ °．

In rectangular ABCD, OD = OC, ﹥ OCD is equilateral triangle, ﹥ CD = CF, ﹥ BDF = 15 degree, ﹥ CDO = ﹥ CDF + ﹥ BDF = 45 degree + 15 degree = 60 degree. In rectangular ABCD, OD = OC, ﹥ OCD is equilateral triangle, ﹥ OC = CD, ﹥ OCD = 60 degree, ﹥ OC = CF, ﹥ OCF = 90 degree - ﹥ OC

Simple calculation of 0.125 × 4 / 11 + 1 × 6.25-12.5% of 8

25-12.5% = 1 / 8 * 11 / 4 + 1 / 8 * 25 / 4-1 / 8 = 1 / 8 (11 / 4 + 25 / 4-1)
=1/8(36/4-1)=1/8*8=1

Knowing the coordinates of two points in the function image, how to find the function analytic expression

I'm glad to answer your question
First of all, you need to make sure that the image is a linear function, a positive scale function, an inverse scale function or a quadratic function
Then write down the relationship, for example
y=ax+b
Then, the coordinates of the two points, X and y, are substituted into the functional relations
Then a and B can be obtained by solving the equation
In this way, we can find the analytic expression of the function

As shown in the figure, ad is the vertical bisector of BC side, if AB = 3 cm.CD=7cm Find the perimeter of the quadrilateral ABCD
Urgent demand!!!

(3+7)*2=20CM

Example: 17km = 17 times 10 to the third power = 1.7 times 10 to the fourth power=_ =________ m

1. Unit conversion: ① 1km = (1000m) = (100000) cm, ② 15cm = (1.5) DM = (0.00015) km, ③ 15kg = (15000) mg = (0.015) t, ④ 1.3 × 10 cubic kg / M cubic = (1.3) g / cm cubic. 2. The density of wood block is 0.6 × 10 cubic kg / M cubic

Given 2x + y = 4, the value of 6x + 3Y is