Set up equations or equations to solve application problems: a sports goods store predicted that a certain brand of sportswear would sell well, so it bought a batch of sportswear with 32000 yuan, which was out of stock soon after it came into the market. The store bought the second batch of sportswear with 68000 yuan, which was twice the quantity of the first batch, but the price of each set was 10 yuan more. How many sets of sportswear did the store buy in two times?

Set up equations or equations to solve application problems: a sports goods store predicted that a certain brand of sportswear would sell well, so it bought a batch of sportswear with 32000 yuan, which was out of stock soon after it came into the market. The store bought the second batch of sportswear with 68000 yuan, which was twice the quantity of the first batch, but the price of each set was 10 yuan more. How many sets of sportswear did the store buy in two times?

Suppose a shopping mall buys x sets of sportswear for the first time. The meaning of the question is: 680002x − 32000x = 10. (3 points) solve this equation and get x = 200. After testing, x = 200 is the root of the equation. 2x + x = 2 × 200 + 200 = 600. A: the shopping mall buys 600 sets of sportswear for two times. (5 points)

An equation problem
(x-650):(y+650)=3:4

(x-650):(y+650)=3:4
4(x-650)=3(y+650)
3y+1950=4x-2600
3y=4x-4550
y=(4/3)x-4550/3

The speed of train a from place a to place B is 60km / h, and that of train B from place B to place a is 90km / h. It is known that a and B are 200km apart. How far is the place where the two trains meet from place a?

Building owner:
Speed ratio of two cars: 60:90 = 2:3
When meeting, the whole journey of car a: 2 ÷ (2 + 3) = 2 / 5
200 × 2 / 5 = 80 km
A: 80 kilometers away from a
Or:
The time of meeting: 200 ÷ (90 + 60) = 4 / 3
4 / 3 × 60 = 80 km

If the solution of the equation 9x-2 = KX + 7 of X is a natural number, then the value of integer k is______ ．

By changing the term, 9x-kx = 2 + 7 and merging the similar term, (9-k) x = 9, because the equation has a solution, so K ≠ 9, then the coefficient is obtained, x = 99 − K. also ∵ the solution of the equation 9x-2 = KX + 7 about X is a natural number, and the value of ∵ K can be: 0, 6, 8. The corresponding natural number solutions are: x = 1, x = 3, x = 9

For a pile of 30 tons of yellow sand, one fifth of the total amount will be used in the first time, and one and a quarter of the amount will be used in the second time. How many tons of yellow sand will be used in the second time?
Use two ways to answer. Wuwu, it's better to be clear. I hate fractions

30*（1/5）*（5/4）
＝6*（5/4）
= 7.5 tons, 30 * (1 / 5) = 6 tons for the first time, and then 6 * (5 / 4) = 7 tons for the second time
30*[（1/5）*（5/4）]
＝30*（1/4）
= 7.5 tons, first find out what fraction of the total amount is used for the second time, which is 1 / 5) * (5 / 4) = 1 / 4, then find out how many tons are used for the second time

Given the line L1: y = 2x + 3, if L2 and L1 are symmetric about the Y axis, then the equation of L2 is______

Line L1: y = 2x + 3 if L2 and L1 are symmetrical about y axis, then the slope of line L2 is - 2, the intersection of line L1: y = 2x + 3 and Y axis is (0, 3), then the equation of L2 is: Y-3 = - 2 (x-0), that is: y = - 2x + 3, so the answer is: y = - 2x + 3

There are 24 boys and 30 girls in class 6 (1)______ %There are more female students than male students______ %There are fewer boys than girls______ %

(1) 30 △ 24, = 1.25, = 125%; (2) 30 △ 24 + 30, = 30 △ 54, = 59; (3) (30-24) △ 24, = 6 △ 24, = 25%; (4) (30-24) △ 30, = 6 △ 30, = 20%; (3) the number of female students is 125% of male students, 59% of female students in the whole class, 2 more than male students

If a + 2B + 3C = 12 and A2 + B2 + C2 = AB + BC + Ca, then a + B2 + C3=______ ．

∵ A2 + B2 + C2 = AB + BC + Ca, ∵ 2 (A2 + B2 + C2) = 2 (AB + BC + Ca), that is, 2 (A2 + B2 + C2) - 2 (AB + BC + Ca) = 0. After finishing, we get (a2-2ab + B2) + (a2-2ca + C2) + (b2-2bc + C2) = 0, that is: (a-b) 2 + (A-C) 2 + (B-C) 2 = 0, ∵ a = b = C, and ∵ a + 2B + 3C = 12, ∵ a = b = C = 2. ∵ a + B2 + C3 = 2 + 4 + 8 = 14

One quarter of the boys in a school are 50 more than one third of the girls. Three quarters of the boys are twice as many as the girls. How many boys and girls are there

Suppose male x female y
x/4-y/3=50
3x/4=2y
The solution is x = 400, y = 150

The equation is x + y = 6, xy = 4, x y =?

X+y=6,xy=4
Then x, y are two roots of the equation T & sup2; - 6T + 4 = 0
t²-6t+4=0
Then T & sup2; - 6T + 9 = 5
(t-3)²=5
So T-3 = ± √ 5
So t = 3 ± √ 5
So x = 3 + √ 5, y = 3 - √ 5
Or x = 3 - √ 5, y = 3 + √ 5