Find x (1) x: 6 / 5 = 25 / 4 (2) 6: x = 12 / 5 (3) 60 / 5 = 2 / 5

Find x (1) x: 6 / 5 = 25 / 4 (2) 6: x = 12 / 5 (3) 60 / 5 = 2 / 5

1.x = 15/2
2.x = 5/2
3.x = 150

Simple calculation: how to do 60 × (1 / 3 + 2 / 5-1 / 2)?

Use the law of association
=60*1/3+60*2/5-60*1/2
=20+24-30
=14

The length and width of a rectangular grassland are reduced by 2 meters, and the area is reduced by 44 square meters?
To list

2 * 2 = 4 (repeated square area)
4 + 44 = 48 (reduced and repeated)
48 / 2 = 24
24 * 2 = 48

The quintic power of 2.8 times 10 is accurate to (), with () significant digits

Accurate to 10000 bits, there are two significant numbers
Because the quintic power of 2.5 times 10 is 280000, so it is accurate to 10000 bits, and there is no need to restore the significant number
I am also the first drop. I am absolutely right

The speed of a train is 54km / h. It takes 57 seconds for the train to pass through a 640km long tunnel (from the front to the rear). What is the length of the train?
Solve the equation with one variable and explain the reason
Yeah, yeah,,,
I have the wrong number
It's 640m, not 640km

The conductor of the train x
54km / h = 54 * 1000 / 3600 = 15m / S
15*57=x+640
x=215
A: the length of the train is 215 meters

In the triangle ABC, G is the center of gravity and makes a straight line intersection through G AB.AC For E.F., AF: FC = 3:2, AE: EB

Because G is the center of gravity, so Ag: GH = 3:2, AF: FC = 3:2, so Ag: GH = AF: FC, so EF / / BC, then AE: EB = AF: FC = 3:2

How many meters is 4.2 light years?

The distance that light travels in 4.2 years, the speed of light is 3 * 100000000 M / s
4.2*365*24*60*60*3*100000000m=39735360000000000m

This is a math problem: I love my parents × 4 = mom and Dad love me, I = (), mom = (), Dad = (), love = ()

I love mom and dad × 4 = mom and Dad love me, I = (1), mom = (9), Dad = (8), love = (0)

As shown in the figure, in trapezoidal ABCD, ad ‖ BC, ∠ B + ∠ C = 90 & # 186;, m.n are AD.BC To prove: Mn = 1 / 2 (BC-AD)
Write for yourself
There is no graph in this question, so we can't add auxiliary lines

It is proved that when passing through point m, let me / / AB intersect BC at point E, and let MF / / DC intersect BC at point F,
Because AD / / BC,
Therefore, both Abem and CDMF are parallelograms,
So be = am, CF = DM,
Because m and N are the midpoint of AD and BC respectively,
So am = DM, BN = CN,
So be = CF, en = FN,
So EF = BC -- ad,
Because me / / AB, MF / / DC,
So angle MEF = angle B, angle MFE = angle c,
Because angle B + angle c = 90 degrees,
So angle MEF + angle MFE = 90 degrees,
So the angle EMF is 90 degrees and the triangle EFM is a right triangle,
And because en = FN,
So Mn = 1 / 2ef (the middle line on the hypotenuse of a right triangle equals half of the hypotenuse),
So Mn = 1 / 2 (BC -- AD)

Given that the 5m power of X is equal to 10, it is necessary to find the 5m power of the algebraic formula (- 2m of 2x) minus 1 / 1000 (the 4th power of x) plus 10

x^(5m)=10
[-2x^(2m)]^5-(x^4)^(5m)/1000+10
=(-2)^5*x^(10m)-x^(20m)/1000+10
=-2^5*[(x^(5m)]^2-[x^(5m)]^4/1000+10
=-32*10^2-10^4/1000+10
=-3200-10+10
=-3200